A 6-yr-old captive-bred male black pine snake (Pituophis melanoleucus lodingi) weighing 0.49 kg with a snout-to-vent length of 127 cm was presented for evaluation of a caudal coelomic swelling that had been present for 3 days. Survey radiographs showed focal distention of the body wall with a mass of soft tissue and mineral opacity. Anti-inflammatory and empiric antibiotic treatments were initiated, with no significant improvement. Coelomic ultrasound showed effusion and intestinal changes consistent with an intussusception. On exploratory celiotomy, the mass was found to be a 10-cm-long colonic diverticulum. A colotomy was performed and inspissated fecal material was removed from the lumen of the diverticulum prior to its resection and closing of the bowel defect. Histological examination of the excised tissue was consistent with an intestinal diverticulum and complete absence of the smooth muscle layers, indicating nonperforating rupture of the bowel wall. The snake recovered uneventfully and began eating 5 days after surgery. On physical and ultrasound examinations 8 months after surgery, the snake's body condition had improved and there was no recurrence of clinical signs, with the snake remaining normal 30 months postsurgery at home.