In humans, type II diabetes mellitus is a condition in which the pancreas is capable of producing insulin but cells do not appropriately respond to insulin with an uptake of glucose. While multiple factors are associated with type II diabetes in humans, a high calorie diet and limited exercise are significant risk factors for the development of this disease. Zoo primates, with relatively high caloric density diets and sedentary lifestyles, may experience similar conditions that could predispose them to the development of diabetes. We surveyed all Association of Zoos and Aquariums (AZA) facilities with primates in their collections to determine the prevalence of diabetes, diagnosis and treatment methods, and treatment outcomes. Nearly 30% of responding institutions reported at least one diabetic primate in their current collection. Although the majority of reported cases were in Old World Monkeys (51%), all major taxonomic groups were represented. Females represented nearly 80% of the diagnosed cases. A wide variety of diagnosing, monitoring, and treatment techniques were reported. It is clear from these results diabetes should be considered prominently in decisions relating to diet, weight and activity levels in zoo-housed primates, as well as discussions surrounding animal health and welfare. Zoo Biol. 32:63-69, 2013. © 2012 Wiley Periodicals, Inc.