How to Get Urine Out of a Mattress (Fresh, Dried, Pet and Foam)
Short answer: Blot up as much liquid as you can without rubbing, lightly mist the spot with a 1:1 mix of white vinegar and cool water, blot again, then cover the damp area with baking soda and leave it for several hours before vacuuming or brushing it away. Finish by drying the mattress completely with airflow before you put sheets back on. For pet urine or stains that have already dried, add an enzymatic cleaner made for urine — that is the step that removes the smell rather than masking it.
Apple cider vinegar can be used in a pinch, but it is not the magic ingredient some recipes suggest. Vinegar works because of its acetic acid, and apple cider vinegar is tinted and contains sugars, so plain distilled white vinegar is the safer, cheaper choice on a light-coloured mattress cover. Everything below works the same way with either bottle — just use white vinegar if you have it.
What you need
- Paper towels or clean white cloths (coloured cloths can transfer dye)
- Spray bottle with 1 part white vinegar to 1 part cool water
- Baking soda (a fresh box absorbs better than an open one from the back of the cupboard)
- A few drops of mild dish detergent — optional, for visible yellowing
- An enzymatic cleaner labelled for urine odour (essential for pets and old stains)
- Vacuum with an upholstery attachment, or a stiff brush and dustpan
- A fan and an open window or two
If you shop for a spray cleaner rather than mixing your own, the US EPA’s Safer Choice program lists products screened for safer chemical ingredients, which is a useful filter for anything you spray on a surface you sleep on.
Fresh accident: the six-step cleanup
- Strip the bed immediately. Sheets, protector, mattress pad, pillows if they were hit. Start a wash on the warmest cycle the care labels allow so urine does not set in the fabric.
- Blot, never rub. Press firmly with towels and work from the outside of the wet patch inward. Rubbing spreads the stain sideways and pushes liquid deeper into the comfort layers. Swap towels as soon as they feel damp.
- Mist the vinegar solution. Dampen the area, do not soak it. Excess liquid is the single biggest mistake with foam mattresses because it takes days to leave the core. Let it sit 10–15 minutes.
- Blot again with fresh towels. Keep pressing until very little moisture transfers.
- Cover with baking soda. An even layer over the still-damp spot pulls out remaining moisture and helps absorb odour. Leave it several hours, or overnight if you can sleep elsewhere.
- Remove the powder and dry. Vacuum slowly with the upholstery tool, then run a fan across the surface until the spot is dry to the touch and smells of nothing.
One chemistry note worth knowing: vinegar and baking soda largely cancel each other out if you mix them in a bowl first. Use them in sequence — acid first, absorbent powder second — rather than combining them into a fizzing paste.
Dried or set-in stains
Dried urine leaves behind salts and residues that need to be re-wetted before anything can lift them, so plan for two passes over two days.
- Find the full extent of the stain in good light — yellow-brown rings often reach further than they first appear, and darker centres usually mean the spot was hit more than once.
- Dab the area with the vinegar solution (add a drop of mild detergent if there is visible yellowing) until the residue softens.
- Lay a sheet of plastic wrap over the damp patch for an hour or two so it does not dry out too fast. This is the trick that makes old stains respond.
- Remove the wrap, blot hard, then apply an enzymatic cleaner per its label. Enzyme formulas break down the organic compounds that hold odour, which vinegar alone does not fully do.
- Finish with baking soda, vacuum, and dry thoroughly. Repeat the enzyme step once more if a faint smell returns as the area dries — odour reappearing on drying is the classic sign of untreated residue deeper down.
For non-urine marks such as sweat, blood or drink spills, the approach differs slightly; see our guide to cleaning stains out of a mattress.
No baking soda? No vacuum? Do this instead
Neither one is mandatory.
- Without baking soda: use the vinegar solution followed by an enzymatic cleaner, blotting between steps, then dry hard with a fan. Enzymes are the real odour remover; baking soda is a moisture and smell absorber, not a cleaner.
- Without a vacuum: let the baking soda dry completely, then sweep it off with a stiff brush and dustpan, or brush it toward the edge of the mattress onto a towel. Never brush damp powder — it smears and hardens.
- Cornstarch or unscented cat litter in a breathable cloth pouch laid on the dry spot can absorb residual odour if you have no baking soda at all. Evidence here is anecdotal rather than tested, so treat it as a stopgap.
Hydrogen peroxide: useful, but with limits
For old, yellowed stains on an innerspring, hybrid or pillow-top mattress, a peroxide mix can lighten discolouration that vinegar leaves behind: 1 cup of 3% hydrogen peroxide, a few tablespoons of baking soda and one drop of dish soap. Apply lightly, let it dry, then brush or vacuum the residue away.
Three cautions. Peroxide has a mild bleaching effect, so always spot-test on a hidden area — near the bottom edge or under the handle seam — and skip it on dark or patterned covers. Avoid it on memory foam and latex, where over-wetting matters more than stain colour. And never combine cleaning chemicals in the hope of a stronger result: mixing bleach with acids like vinegar, or with ammonia-based cleaners, can release toxic gases, as the Washington State Department of Health explains. Use one product, rinse-blot, dry, then try another if needed.
Mattress type changes the method
| Mattress type |
Best approach |
Avoid |
| Memory foam |
Fine mist of vinegar solution, enzyme cleaner, long drying time with a fan |
Soaking, peroxide, high heat, hair dryers on hot |
| Latex |
Light blotting and minimal moisture; dries slowly |
Saturation and prolonged direct sun, which degrades latex |
| Innerspring |
Vinegar solution, baking soda, peroxide mix on light covers after a spot test |
Letting liquid run down into the coil layer |
| Hybrid / poly foam |
Enzyme cleaner plus airflow that reaches the comfort layer |
Over-wetting the quilted top |
| Pillow-top |
Spot treat only; the extra padding holds moisture |
Peroxide on the quilted panel without testing |
Foam holds water far longer than coils do, which is why every foam instruction above says “mist, don’t soak.” If you are weighing up a replacement and want to understand the difference in construction, our comparison of memory foam and spring mattresses covers how the layers are built.
Dog and cat accidents
Pet urine is usually more concentrated than human urine and tends to recur in the same spot, because animals are drawn back to a scent they can still detect even when you cannot. That makes enzymatic cleaners the priority rather than the backup step. Saturate the affected area per the label, cover it loosely so it does not evaporate before it finishes working, then blot and dry. Expect to repeat on a set-in spot.
Two specifics for pets: skip any cleaner containing ammonia, since urine itself smells of ammonia and can re-mark the area in your pet’s mind — guidance echoed by Humane World for Animals. And if house-soiling is new, frequent or accompanied by straining, book a vet visit; urinary tract infections, bladder stones, diabetes and kidney disease all show up this way before they show up anywhere else.
Drying: the step people rush
A mattress that feels dry on the surface can still be damp two inches down, and trapped moisture is what causes musty smells and mildew later. Give a lightly treated spot a few hours with a fan aimed across it; give a saturated spot the rest of the day and overnight. Stand the mattress on edge if you can, so air reaches both faces. Room-temperature airflow beats heat: high heat can stress foam and adhesives, and prolonged direct sunlight fades and degrades foam and latex. A short airing in indirect light is fine; leaving a foam mattress baking on a patio is not.
Mistakes to avoid
- Rubbing instead of blotting — it drives urine deeper and widens the stain.
- Pouring liquid on rather than misting it.
- Using bleach, which can damage covers and foam and leaves its own harsh smell.
- Vacuuming damp baking soda, which clogs the powder into the fabric and your filter.
- Remaking the bed before the spot is bone dry.
- Skipping a spot test with peroxide or an unfamiliar spray.
Preventing the next one
A waterproof mattress protector is the only prevention step that works every time. Choose one with a breathable knit or Tencel top over a thin polyurethane barrier rather than a crinkly plastic sheet, check the pocket depth against your mattress, and wash it on the schedule the label sets so the barrier survives. Keeping a spare fitted sheet and a washable pad in the room turns a 2 a.m. accident into a five-minute job.
For children, a bathroom trip at bedtime and less fluid in the last hour help, and waterproof layers take the pressure off everyone. Bedwetting is common in young children and usually resolves on its own, but the National Kidney Foundation advises talking to a doctor when it continues in older children or starts again after a dry period, since it can have a treatable medical cause. If you are buying for a child’s room, our notes on choosing a toddler mattress cover wipeable, breathable options.
When to call a pro — or replace the mattress
Consider professional upholstery cleaning if the accident was large, repeated in the same place, or is on a mattress you cannot move outdoors. Ask specifically whether they use enzyme treatments and low-moisture extraction that is safe for foam. Replacement is worth considering if odour survives several enzyme treatments and full drying, if the core feels permanently damp, or if you see mould growth — none of which home cleaning reliably fixes. Age matters too; if the bed was already sagging, see how often you should replace a mattress before spending money on cleaning.
FAQ
Does apple cider vinegar work as well as white vinegar? Chemically it acts the same way, since both rely on acetic acid. White distilled vinegar is preferred because it is colourless and contains no sugars that could leave residue.
Will vinegar alone get rid of the smell? Often on a fresh accident, yes. On dried or pet urine, no — you need an enzymatic cleaner to break down what is left behind.
How long before I can sleep on it? Until it is fully dry to the touch with no damp coolness and no smell. With a fan, a small treated spot is usually ready the same day; a soaked area may need overnight.
Can I mix vinegar and hydrogen peroxide? Don’t. Use them as separate treatments with drying in between, and never mix either with bleach or ammonia-based products.
Do essential oils help? They add scent, not cleaning power, and heavy use can irritate sensitive skin or airways. If you use them, a drop or two in the vinegar mix after the mattress is clean is plenty.
Is a UV flashlight useful for finding old spots? It can make dried urine easier to see in a dark room, which helps you treat the whole area rather than just the visible ring. It is a locating tool, not a cleaning one.
Updated September 2026.
