[Lucy Lake]

Sometimes when a cat won't use the litter box, it is his/her way of letting you know he/she is having bladder problems, maybe pain when urinating.
A trip to the vet for a check of urine (for blood,) antibiotics if necessary, and a diet change will usually clear up the problem.

There are special cat foods for cats who have urinary problems. The vet can recommend the proper food.
Having several bowls of water setting around the house encourages the cat to drink.

[secret garden]

I appreciate the advice but he's healthy as a horse, according to my vet who says complaints about inappropriate urination are the number one thing he hears about cats. I've even resorted to kitty psych books and bought the expensive stuff that takes out the odors. He uses the box almost all of the time. He's an only cat so it's not a territory problem and he has a room with privacy so it's not that either. I think he's just spiteful and maybe a little dense. But gorgeous to look at and fairly sweet in nature. In the meantime, I'll get out the oven mitts and hold him down for nail clippings.