Abstract: Odors associated with the use of toilets are reduced by providing a water driven positive ventilation fan which pumps undesirable odor bearing gases from the toilet bowl and discharges them into the sewer through an auxiliary passage built into the toilet base. Operation of the ventilated toilet is automatic. Water valves coupled to the toilet seat and lid hinges turn on the fan's water turbine when the lid is raised and weight placed on the seat. The fan turbine shuts off automatically when this condition is no longer satisfied. An automatic blocking valve is provided in the auxiliary passage to prevent back-streaming of sewer gas. This gas blocking valve opens automatically when the fan is in operation and closes when the fan shuts off. No electrical connections are required.