Background: A captive adult male saddleback tamarin, Saguinus fuscicollis, was lethargic, unresponsive to its surrounding and died before medical care. Methods: Necroscopic, histopathological and immunohistochemical examinations were performed. Results: Neoplastic spindle cells of the urinary bladder were positive for antifactor VIII antibody. Conclusion: A primary urinary bladder haemangiosarcoma was diagnosed, and it has not been previously reported in non-human primates. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.