Large photoinduced Faraday rotations of the polarization direction of a probe beam traveling through a semimagnetic semiconductor are obtained at temperatures higher than that of liquid nitrogen when a pump pulse is sent through the material. These rotations are quasiproportional to the photoinduced free‐carrier density and the applied magnetic field and are strongly resonant with the band‐gap‐probe frequency detuning. A model based on the free‐carrier induced saturation of the refractive indices explains well the experimental observations. The high values obtained for the photoinduced polarization rotations (more than 1° pJ−1 &mgr;m2) make such a process attractive for the design of optical signal processing devices. ©1995 American Institute of Physics.