We report the use of hypervariable simple sequence repeat (SSR) nuclear loci to study paternity in a community of wild chimpanzees (Pan troglodytes schweinfurthii) in Gombe National Park, Tanzania. All 43 living members of a habituated community were sampled and 35 were genotyped at 8 SSR loci using DNA amplified from hair. Paternity exclusions were performed for 25 chimpanzees including 10 for whom the mother was also genotyped. In each case 12-20 males were potential fathers based on their age and/or direct observation of sexual behaviour. 179 tests involving potential father/offspring combinations were performed. In four cases the data permit the probable identification of the previously undetermined father; these are the first such determinations for free-ranging chimpanzees, and the first based on non-invasive sampling. In another four cases we were able to exclude all but two to five potential fathers, and in the remaining cases we were able to exclude all living males. For molecular ecologists SSR genotype databases offer important advantages over currently popular minisatellite DNA finger-printing: they can be analysed unequivocally using traditional population genetics techniques and they can be expanded through time and space by other researchers.