Perforation is the rarest complication of the duodenal diverticulum (DD), but it is the most serious complication. Mortality rate was reported up to 30%, which may be related to diagnostic delay because the symptoms of the perforated DD are vague and nonspecific. Therefore, accurate diagnosis is important to improve the clinical outcome. Surgical treatment was considered as the standard therapeutic option. However, surgical intervention may increase morbidity and mortality due to surgical complications. Therefore, nonoperative management can be considered in some patients with perforated diverticulum who have stable vital signs without generalized peritonitis, or in elderly patients with comorbidities. Several case reports of nonoperative management of perforated DD have been reported. Herein, we describe a patient with perforated DD diagnosed based on a computed tomography scan, who was successfully treated with conservative treatment.