Current‐voltage characteristics of hot electrons are analyzed for negative resistance regions. Electrons in a homogeneous semiconductor are assumed to interact only with acoustical phonons and charged centers of heavy mass. These charged centers could be ionized impurities or heavy holes with a negligible contribution to the current. A distribution function which ignores electron‐electron collision almost certainly does not lead to negative resistance. A postulated Maxwellian distribution may lead to a current discontinuity, but does not lead to a stable region of negative resistance, contrary to previous conclusions. For any physical distribution it is shown that the average electron energy increases monotonically with field strength. These results also apply to situations in gaseous discharge where hot electrons are scattered by neutral molecules and ions.