Atmospheric neutrinos

The results of experiments on atmospheric neutrinos are summarized, with th e important exception of Superkamiokande. The main emphasis is given to the Soudan-2 and MACRO experiments. Both experiments observe atmospheric neutr ino anomalies in agreement with nu(mu) --> nu(tau) oscillations with maximu m mixing. The nu(mu) --> nu(s) oscillation is disfavored by the MACRO exper iment at 2 sigma level.