Aulacochthebius libertarius sp. n. is described from the Moroccan Anti Atlas. The aedeagus of A. exaratus (Mulsant) and A. narentinus (Reitter), the two other known Palaearctic species of the genus, are figured, and their similarities discussed. The Palaearctic species of Aulacochthebius do not seem to form a natural group, A. narentinus and A. libertarius sp. n. being more similar to some Ethiopian and Oriental species.