We investigated the ultrafast energy relaxation of photoexcitedminorityelectrons in highly dopedp‐GaAs by means of femtosecond time resolved luminescence (&Dgr;t<90 fs). Our experiments allow the first observation of the extremely fast cooling of minority electrons within the &Ggr;‐valley. The electron mean energy decreases within 150 fs from 150 meV down to less than 50 meV. The total energy loss rate reaches values higher than 10−7W per electron, representing the highest energy loss rates of electrons observed to date in monocrystalline semiconductors. Ensemble Monte Carlo simulations show that the electron‐hole scattering is responsible for these high energy loss rates. ©1995 American Institute of Physics.