Members of the large grasshopper genus Orthochtha are widely distributed throughout the Afrotropics with some representatives in India and the Far East. The taxonomy of the genus has, however, long been recognized by acridologists to be unsatisfactory. This publication provides a thorough revision of Orthochtha together with seven allied genera, of which three are erected here. In all, 36 species and 11 subspecies are treated, of which 16 species and 5 subspecies are described here as new. All taxa are diagnosed, illustrated, keyed, mapped and their affinities discussed. The biogeography of the group is considered and a synopsis of the available information of the biology, ecology and economic importance given for each species. This book will be of use both to taxonomists and to agricultural field workers, particularly in Africa.