A 65-year-old woman presented with an 8-year history of progressive frontotemporal alopecia and hirsutism. She had elevated serum levels of testosterone, androstenedione and estradiol. Ultrasound and computed tomography imaging suggested a right ovarian mass, while bilateral ovarian venous sampling demonstrated increased testosterone levels originating from both ovarian veins. Histology obtained following bilateral oophorectomy demonstrated bilateral ovarian hyperthecosis. Six months after surgery, the patient remains well with no progression of the alopecia. Ovarian hyperthecosis is a rare cause of androgenetic alopecia in postmenopausal women. The role of hyperthecosis and its relationship to androgenetic alopecia is reviewed.