A 51-year-old postmenopausal multipara with high plasma testosterone levels and virilization, as demonstrated by hirsutism, balding, increased libido, and clitoromegaly, is presented. The plasma testosterone levels exceeded 330 ng/dl on 3 occasions. The plasma androstenedione, urinary 17-ketosteroids, and 17-hydroxycorticosteroids, as well as the computed axial tomography scan of the adrenal glands were normal. Although no pelvic mass was detected by sonography or pelvic exam, the patient was found to have small bilateral hilus cell tumors of the ovary. Following total abdominal hysterectomy and bilateral salpingo-oophorectomy, the plasma testosterone dropped to 14 ng/dl. This is the second case of bilateral hilus cell tumors of the ovary to be reported.