We report a case of a perforated duodenal diverticulum that was diagnosed by computed tomography and treated by laparoscopic diverticulectomy. A 61-year-old woman visited the emergency room complaining of severe, sudden abdominal pain with nausea and vomiting. Computed tomography showed a round space containing air bubbles and food material in the posterior aspect of the second duodenal portion. The patient underwent an emergency laparoscopic exploration. Entering the posterior side of the duodenum, dirty reactive fluid was drained and an ∼4-cm perforated diverticulum was revealed at the posterolateral aspect of the second duodenal portion. After completing the peridiverticular dissection, a diverticulectomy was performed using ultrasonic shears, and the opening of the diverticulum was closed in two layers using intracorporeal hand-sewn sutures. She was discharged on postoperative day 10 without complications. To our knowledge, this is the first report of laparoscopic resection of a perforated duodenal diverticulum.