A waterfall aquarium including an enclosed transparent water tank having an interior and exterior. A water exit conduit communicates the interior of the water tank with the exterior thereof. The water exit conduit includes a hollow tubular body having an exit end and an intake end, with the intake end thereof being located below the exit end. The water tank rests upon a base having an interior and an exterior. A water pump is located within the interior of the base. The water pump has an inlet and an outlet, the inlet communicating with the interior of the base and the outlet communicating with the interior of the water tank. A water receptacle is adapted to receive water from the water exit conduit and return the water to the interior of the base.