A 47-yr-old multiparous female bonobo (Pan paniscus) tested positive for pregnancy on a routine urine test. Because this geriatric animal was considered postreproductive, oral contraception had been discontinued. Sequential transabdominal ultrasound evaluations were performed under voluntary behavior and revealed that the uterus contained a mass of heterogenous tissue which was rapidly increasing in size. Due to a lack of normal fetal development and the ultrasonographic appearance of the uterine tissue, a molar pregnancy was suspected. Ovariohysterectomy was performed, and a complete hydatidiform mole was confirmed through human chorionic gonadotropin levels as well as gross and histological examination of the uterus. To the authors' knowledge, this is the first time a complete molar pregnancy has been reported antemortem in a nonhuman great ape, although a single case of partial hydatidiform mole was previously documented in a chimpanzee on postmortem examination. This case describes the successful medical and surgical management of complete molar pregnancy in a bonobo and provides support for extending the age range of birth control recommendations in geriatric captive great apes that exhibit active breeding behavior.