• A dirty litter box causes your cat to eliminate outside of the box.BananaStock/BananaStock/Getty Images
  
  At least 10 percent of cats eliminate outside their litter box due to a variety of issues, according to the American Society for the Prevention of Cruelty to Animals (ASPCA). When this happens have your cat checked by a veterinarian to rule out any medical problems for the behavior. If it continues you can take several steps to stop it and get your cat to use its litter box properly.
  
  

Unclean Litter Box

• Cats will not use an unclean litter box, because they have a sensitive sense of smell. Most cats, according to the ASPCA, prefer clumping, unscented litter. Clean your cat's litter box at least once a day by scooping it free of urine clumps and feces. Empty the litter box weekly and scrub the litter box itself with baking soda, unscented soap or an enzymatic pet cleaner. After you dry the box add fresh litter. Never use harshly scented cleaning chemicals like bleach or ammonia as this can cause your cat to eliminate outside the box just as a dirty litter box would.
  
  

Too Few Litter Boxes

• Sometimes cats don't use the litter box when there are too few of them. The Humane Society of the United States (HSUS) recommends one more litter box than the number of cats in your home. If you have one cat, you need two boxes, two cats need three and so on. Place at least one litter box on each level of your home to ensure your cat will have one nearby whenever it needs to eliminate. Do not put all litter boxes in one location; spread them out so each of your cats has a separate space to feel safe.
  
  

Litter Box Location

• Place litter boxes for your cats in quiet, easily accessible locations. Keep litter boxes away from high-traffic areas of your home or other noisy areas, such as a washing machine or dryer. Provide free access to the litter box's location at all times. If you put a box in a separate room or closet with a door, install a cat-sized access door or hole. Place the litter box away from your cat's food, water bowl or bed, as cats will not eliminate where they eat or nest, according to the Summerlin Animal Hospital.
  
  

Type of Litter Box

• Your cat needs a litter box large enough for it. Smaller boxes may cause your cat to accidentally eliminate outside the box that's too small. Young kittens and geriatric cats with arthritis find litter boxes with tall sides difficult to use. Provide a box with low sides so your cat can easily enter and exit the box. Some cats prefer open rather than hooded litter boxes as they feel vulnerable in small, enclosed spaces. If your cat will not use a covered litter box, provide an open one.