The invention is directed to a pet litter box that has a lower portion having a bottom wall and four lower portion side walls that are at slightly more than ninety degrees from the bottom wall. An upper portion has a top wall and four upper portion side walls. A cutout portion in one of the four upper portion side walls forms a pet ingress and egress point. The four upper side walls terminate in a groove that mates with a lip formed by the four lower portion side walls. An internal divider has a floor grate that extends along a length of the lower portion and has a wall at approximately ninety degrees to the floor grate. The wall does not extend the length of the lower portion. Note that the lower portion has a height that is equal to or greater than the height of the upper portion.
