We describe a case of multiple pathologic fractures in a woman with Cushing's syndrome during pregnancy. Pathologic fractures were seen in the pubic and ischial bones and in T12 and L1 of the vertebral body. These findings, accompanied by easy fatigue, amenorrhea without nursing, psychological disorder, and premature birth, were retrospectively compatible with those of Cushing's syndrome, not pregnancy-associated osteoporosis. After adrenalectomy, the pain in her groin and back ceased. Plain radiographs showed healing of the fractures and increased mineralization. This case demonstrates the need to be alert to the possible presence of metabolic bone disease, including Cushing's syndrome, when we encounter multiple pathologic fractures with osteoporosis in young patients, even if the patient is pregnant.