An odor extraction device (1) for a toilet having a pan (2) and a cistern (4) is disclosed. The extraction device (1) includes an inlet (3) and an outlet (5). The inlet (3) is adapted for gas communication with an interior of the toilet pan (2) above the water level in the pan (2). The outlet (5) is in gas communication with the inlet (3). The outlet (5) is also adapted for gas communication with a sewerage pipe (6). A suction means, in the form of an impeller fan (7), is provided intermediate the inlet (3) and the outlet (5) for drawing gas from within the pan (2) in through the inlet (3) and out through the outlet (5). To prevent backflow of unpleasant odors from the sewerage pipe (6) to the pan (2), a one way valve (8) is provided between the inlet (3) and the outlet (5).