Abstract: A pet enclosure and waste tray system includes a rectilinear cage, an detachably integrated waste pan removably attached to the bottom portion of the cage, a molded waste tray into which the combination cage and waste pan may be nested, and a dolly upon which the waste tray securely fits. The rectilinear cage has a movable rectilinear section capable of being swung up and away from the cage to facilitate removal of enclosed pets. Nesting material may be introduced into the waste pan which supports and is spaced from the bottom portion of the cage. Due to the proximity of the waste pan to the wire mesh of the bottom of the cage, the nesting material penetrates the cage for the occupant's use. A continuous shoulder along the inside of the waste tray is dimensioned such that the cage is supported by the shoulder when nested within the waste tray. The waste tray has a downwardly curled upper lip receivable on railings extending upward from the dolly to securely support the tray-pan-cage combination.