Diffuse hemangioma of the pregnant uterus is a serious lesion. We report the first case of a successful cesarean section at term following expectant management of pregnancy in a patient with presumed isolated diffuse cavernous hemangioma of the uterus and protein S deficiency. The sonographic diagnosis and clinical management of this condition is described. The presented successful pregnancy underlines that, under close surveillance, consideration should be given to a conservative approach to this sonographic finding during pregnancy, as even an abdominal delivery does not imply hysterectomy inevitably.