Rationale:Adult granulosa cell tumors (AGCT) mainly secret estrogen, but few androgens. It is rarer to have amenorrhea and hyperandrogenemia as clinical features. Here, we report a rare case of right side AGCTs with amenorrhea and hyperandrogenemia in a 19-year-old female.Patient concerns:The 19-year-old patient was admitted to our hospital due to amenorrhea for more than 1 year, and discovery of pelvic mass for 4 months. The gynecological ultrasound and computed tomography (CT) cannot define the nature of the mass. Surprisingly, an elevation in testosterone levels was also measured.Diagnosis and interventions:The present patient underwent laparoscopic right salpingo-oophorectomy and partial omentectomy and biopsy of the peritoneum.Outcomes:After the surgery, the testosterone value was down to normal. The patient menstrual cramps on August 13, 2021. Her clitoris is smaller than the front. Up to August 1, 2022, there was no obvious sign of recurrence.Lessons:Androgen-secreting AGCT is rare. We hope that this case can strengthen gynecologists’ early diagnosis and treatment of this disease and improve the prognosis.