PURPOSE: To present a rare case of Sertoli cell tumor that presents with acute abdomen. CASE: A 28-year-old patient with symptoms of acute abdomen has presented to our emergency department. Her examinations revealed a 12 × 10 cm heterogeneous mass in the right ovarian fossa. Laparotomy was carried out immediately. Frozen pathological study revealed a low-grade sex-cord stromal cell tumor. Right salpingo-oopherectomy was performed. During 2 years of follow-up, there was no evidence of disease. CONCLUSION: Although rupture of a malignant ovarian tumor is an infrequent cause of acute abdomen, it should be considered in the differential diagnosis of acute abdomen.