Why is my cat urinating outside the litter box?

Cats do that a lot if the litter box is too full and they don't want to go in it but they know where they should be going. Also, if you have another cat, it could be deciding that it doesn't want to share the box. In this case you would put another litter box out and they will pick which one to use. The only other thing i can say is think about what has changed recently? A new brand of litter, a new cat, a change in the frequency of cleaning the litter box,it could even be that she is getting too old and it hurts to get into the litter box.Good luck.. Hope I helped!

Is she standing in the box while she is doing it? Maybe the box is too small, or the sides aren't high enough. My cat would stand in her litter box, but her bottom would hang over the side of the box, got a bigger box with high sides and its all good now. Also,try another type of litter, cats can be fussy with litter.

If the litter box is clean, then I would suspect a urinary tract infection. A simple visit to the vet and some antibiotics should take care of it.