A diagnosis of coenuriasis was made in a spectacled langur raised in captivity. Multiple cysts removed from the subcutaneous tissues and later from the abdominal cavity were identified as coenuri, typical of the genus Taenia. Post-surgical treatment of the remaining cysts with praziquantel was assessed with whole body computerized tomography (CT). CT at 6 weeks post-treatment revealed a reduction in size and increased calcification of abdominal cysts as compared to pretreatment CT. Cyst fluid antigens in ELISA assays showed a high titer (1:5, 120) IgG response in the langur serum, while no IgM response could be detected. No decrease in IgG titer was seen 6 weeks after treatment. Immunoblot analyses identified several parasite-specific antigens with apparent molecular weights of greater than 92.5 (3 bands), 88, 41, 37, and 34 kDa.