Functional cysts and benign neoplasms are the most common ovarian masses among young adolescents. Ovarian cancer on the other hand, although rare in this age group, is the most common genital tract malignancy. The purpose of this study was to define imaging characteristics of ovarian masses in adolescents between 12 and 21 years old and correlate imaging and surgical findings. Thirty-seven female adolescent patients aged between 12 and 21 years were operated on because of a diagnosed ovarian mass between 1997 and 2002. All patients underwent pelvic ultrasound, five had an abdominal CT scan, two had abdominal MRI, one abdominal X-ray and one intravenous pyelography. Ultrasound was used to define the size of the lesion and to characterize its gross morphologic condition as solid, simple cyst or complex cyst. The records were reviewed for age at presentation, presenting symptoms, diagnostic studies, surgical procedure and pathology findings, which were available for all patients. In our study 32 patients (86.5%) were symptomatic and five asymptomatic (13.5%). The most common presenting symptom was abdominal pain (59.5%). Thirty-four patients (91.1%) had benign lesions, two had malignant tumors (5.4%) and one patient had a borderline lesion (2.7%). The most common ovarian masses detected were germ cell tumors (27.5%) and functional cysts (25%). Twenty patients (54%) underwent operative laparoscopy and 17 patients (46%) exploratory laparotomy. Simple resection of the ovarian mass was achieved in the majority of cases (84%). Bilateral salpingo-oophorectomy was performed in only one case (2.7%).