The grease trap is a device that may be attached to the drainpipe of a sink and the outlet pipe of a plumbing system to remove grease from wastewater before it enters the plumbing system. The device uses simple principles of gravity and separation of immiscible liquids to achieve this goal. Also provided with the present invention is a vent pipe to decrease the production of unpleasant odors. A covered opening is provided for removing the grease periodically.