First, how old is your dog? What kind of breed is he? How many times a day do you take him out? Do you see a pattern in the peeing?

You need to make sure you clean up the mess and make sure it is clean very good. Your dog can probably smell the pee and go there again and again. You must keep him in a crate. If he keeps going to the bathroom out side of the crate, put wood around a crate. I do the with my dog. If you catch him in the act again, say "No" sternly, and rush him outside. Do not let him go in the house. Good luck!