How to Get the Urine Smell Out of a Mattress (Step-by-Step Guide)

Few household smells are as stubborn as urine on a mattress. Whether it's a child's bedwetting, a pet accident, or an unwell night, the odour has a way of lingering long after the stain looks gone — and coming back on humid days. The good news: with the right method (not just soap and water) you can fully remove it. Here's exactly how to get the urine smell out of a mattress, the home remedies that actually work, and how to make sure you never have to do this again.

Urine isn't just water — as it dries, it leaves behind uric acid crystals that ordinary cleaning can't dissolve. Plain water and detergent rinse away the surface, but the crystals stay buried in the mattress fibres. Then, whenever the air gets humid, those crystals release that sharp ammonia smell all over again. That's why a mattress can seem clean and still smell on a damp day. To truly remove the odour, you have to break down the crystals, not just rinse the surface.

1. 1Blot, don't rub. Press clean towels firmly onto the area to soak up as much liquid as possible. Rubbing only pushes urine deeper into the mattress.
2. 2Spray with vinegar solution. Mist the area with a 1:1 mix of white vinegar and water until lightly damp (not soaked). Let it sit 10–15 minutes, then blot again.
3. 3Cover with baking soda. Sprinkle a generous, even layer over the whole damp area. It pulls out remaining moisture and odour as it dries.
4. 4Wait, then vacuum. Leave the baking soda for at least 8 hours — overnight is ideal. Then vacuum it all up with an upholstery attachment.
5. 5For old or strong smells, use an enzyme cleaner. If any odour remains, apply an enzyme cleaner per its label, let it dwell the full recommended time, and air dry. This is the step that breaks down the uric acid crystals for good.
6. 6Dry completely. Point a fan at the mattress or stand it in sunlight until bone dry before putting bedding back on. Any trapped moisture will reignite the smell.

Not every DIY fix is equal. Here's how the common ones compare:

A popular DIY blend for stubborn cases is 3% hydrogen peroxide, a few tablespoons of baking soda, and a drop of dish soap — effective, but always spot-test on a hidden corner first, since peroxide can lighten coloured fabric.

A few common missteps make the problem worse: over-soaking the mattress (moisture gets trapped and turns to mildew), using ammonia-based cleaners (they smell similar to urine and can encourage pets to re-mark), reaching for bleach (harsh, damaging, and risky mixed with other cleaners), and skipping the drying step — the single most common reason the smell comes back.

Cleaning urine out of a mattress is a slow, smelly job — and the only way to avoid repeating it is to stop liquid from reaching the mattress in the first place. A quality waterproof mattress protector creates a barrier that urine, spills, and sweat simply can't get through. When an accident happens, you unclip the protector and machine wash it in minutes — the mattress underneath stays bone dry and odour-free. Vastrora's protector pairs a soft cotton terry top with a silent, breathable TPU membrane, so it feels like a normal fitted sheet, not a crinkly plastic cover. The simplest way to avoid the problem entirely is a waterproof protector for kids and bedwetting — accidents stay on the surface and wash off, never reaching the mattress. If you're weighing options, our buying guide to the best waterproof mattress protectors in India walks through what to look for.