Background A dead male Hamadryas baboon, Papio hamadryas, from a zoo in Samsun in northern Turkey was submitted for necropsy examination. Methods Standard techniques were performed for necropsy and for parasitic identification. Results A total of 14 nematodes were recovered from the small intestine. All nematodes were identified as Aonchotheca annulosa. Conclusions This nematode is most often reported from murid rodents under natural conditions. To date, little is known about the occurrence of A.annulosa in monkeys, with the exception of a single report in a capuchin monkey. This is the first record of A.annulosa from P.hamadryas.