We present an unusual case in which a 23-year-old nulliparous patient was noted to have bilateral multicystic adnexal masses at 21 weeks gestation. Subsequent severe nausea, vomiting, and hyperglycemia with a serum glucose level of 450 mg/dL led to the diagnosis of gestational diabetes. Gradual development of marked maternal virilization ensued and was associated with a serum testosterone level of 4030 ng/mL (free testosterone level of 224 pg/mL), with normal serum dehydroepiandrostendione, estriol, and cortisol levels, leading to the diagnosis of hyperreactio luteinalis. Following vaginal delivery at 38 weeks gestation, gradual and complete spontaneous resolution of signs, symptoms, adnexal masses, diabetes, and testosterone levels were documented.