Abstract: A letter opener comprises a housing which is sized to be conveniently held in one hand. An externally accessible groove extends along a side of the housing, the groove having an upper wall, a bottom wall, and a side wall. A blade partially protrudes into the groove through the upper wall at a distance from the side wall. A rocker is provided which can rotate around a rocker axis. The rocker comprises a front section forward of the rocker axis and a rear section rearward of the rocker axis. The front section of the rocker is arranged opposite the blade and, in use, pushes an envelope into the blade.