Urine stains on mattresses from pets and people can create an overpowering odour and an unsanitary sleeping place, but a thorough cleaning and preventive measures will extend the life of your mattress. Open the windows and run a fan as you clean, if possible, to help remove urine odour from the air in the room. Remove mattress urine odour with basic household supplies, and consider using a plastic protective sheet to prevent damage from future accidents.
Locate the urine stain on the mattress by looking for fabric discolouration or sniffing around each portion of the mattress.
Pour white distilled vinegar on the stain until it is thoroughly saturated, and allow it to set for approximately five minutes. The vinegar will soak through the mattress and kill bacteria as it absorbs odour.
Blot the vinegar out of the mattress with paper towels. Apply pressure to the towels by leaning into them or by setting heavy objects on them, and repeat this process with dry paper towels until you have absorbed most of the vinegar.
Pour baking soda over the area, and leave it there overnight. Baking soda will absorb some of the remaining moisture while neutralising odour.
Vacuum the baking soda from the mattress.
Scrub the mattress with upholstery cleaner, if desired, according to the product's directions.
Try an enzyme-based cleaner, such as Bio-Kleen or Nature's Miracle, if the problem persists. Place bowls of vinegar or open boxes of baking soda in the room to absorb odours from the air.