Abstract: A prefabricated shower module with a bottom and low side walls and a slightly lower front wall which has a horizontal outward projecting lip. The bottom preferably has a gentle downwardly sloping pitch leading to a drain hole with recesses for a strainer, so that water puddles are not formed in the bottom. The inside surfaces of the bottom and the walls are roughly textured so that they are well adapted for holding ceramic tiles attached thereto by means of thinset adhesive. The upwardly-facing edges of the walls are adapted to mate with wall boards forming the inner upper walls of the shower enclosure. The use of the shower module enables a workman to readily install a shower enclosure that is both watertight and has true and plumb surfaces.