BACKGROUND Adnexal torsion is a gynecologic emergency that dictates immediate surgical intervention. Twisted ovarian cysts are rare in adolescents, but they can cause significant distress to patients. Idiopathic ovarian torsion is uncommon in adolescents and the incidence is reportedly higher in women aged 20 to 40 years. Most twisted cysts in adolescents are benign. In the past, oophorectomy was commonly performed for a torsed ovary, but currently there is a trend toward ovary preservation. The diagnosis of twisted ovarian cyst is based on pathognomonic symptoms and findings from a focused clinical examination and ultrasound. Because the differential diagnosis includes acute appendicitis and gastroenteritis, referral to a gynecologist may be delayed. CASE REPORT We present the case of a huge, twisted ovarian cyst in a 16-year-old girl who presented with an acute abdomen. The initial diagnosis was acute appendicitis, which delayed her referral to a gynecologist. An emergency laparotomy and left salpingo-oophorectomy were performed. The histopathology of the ovarian cyst was reported as serous cystadenoma. CONCLUSIONS The optimal management of a twisted ovarian cyst in adolescents is the subject of much debate. Here, we review the literature on ovarian torsion in children and adolescents. The patient in the case we present had a twisted ovarian cyst that was managed with salpingo-oophorectomy.