This study of a group of semi-free-ranging Barbary macaques Macaca sylvanus aimed to determine paternity, to establish whether any individual male achieved prominent mating success and to assess genetic variability. Analyses involved electrophoresis of 15 blood protein systems and multilocus DNA fingerprinting (isotopic and nonisotopic). Genetic variability was low; only two blood protein systems were polymorphic. Although all DNA-fingerprints were individual-specific, they showed a high average band-sharing index value (0.67). Nevertheless, a combination of all methods permitted inference of paternity in 11 out of 15 (73%) cases tested. Several males from different age classes fathered infants.