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., (© 2012 John Wiley & Sons A/S.)