In 1989 an experiment was started at the Bukhara Breeding Centre, Kyzylkum Desert, Uzbekistan, to discover whether zoo-bred Przewalski's horses Equus przewalskiicould adapt to semi-wild desert conditions. One stallion and four mares of different ages were released into a 5126-ha fenced area and monitored over a period of 17 years. This paper presents the information gained from the studies concerning home ranges, interactions with other ungulate species, adaptation to new food resources and comparative changes in daily activity. The results of breeding and changes in the structure of the group are also presented. The horses appeared to adapt well to the new conditions and there appeared to be no negative effects of interspecific interaction with introduced kulans Equus hemionus kulan in the release area.