A 16-year-old male, white-collared lemur (Eulemur cinereiceps) was presented for lethargy, anorexia and nausea. General examination showed dehydration and icterus. Blood analysis revealed neutrophilic leucocytosis and elevated hepatic enzyme concentrations. Abdominal CT scan revealed two biliary calculi and a dilatation of the pancreatic and common bile ducts, indicating biliary obstruction. Due to lack of response to supportive treatment (intravenous fluid therapy, long-acting amoxicillin, tramadol, omeprazole, methionine, silybin), cholecystoduodenostomy was performed, and a hepatic granuloma and gallstone were removed. The animal recovered from the surgery within a week and blood parameters were within normal range 3 weeks later. Microbiological evaluation of the calculus revealed an Enterococcus casseiflavus biliary infection, and hepatic cysticercosis by Taenia martis was diagnosed by histology and PCR. Cholelithiasis has been described in primates, but successful surgical treatment is rare. To the authors' knowledge, this is the first description of an obstructive cholelithiasis treated successfully by cholecystoduodenostomy in a primate.