We present an extreme case of Gigantomastia in pregnancy in a 24-year old woman, gravida 2, in a 28 weeks' of gestation, with a total breast weight of 33 kg, complicated by infection, ulcerations and subsequent hemorrhage. Thorough laboratory analyses did not reveal any hint as to the cause of this enormous breast enlargement. Gynecological examinations and ultrasound revealed a viable, progressive normal fetus. The severity of the problem is further emphasized by the patients' breathing problems and even big difficulty in standing and walking. We performed bilateral simple mastectomy as a life-saving procedure to prevent fatal complications. The procedure finished without any complications or large amount of blood loss. There are less than 100 cases of gravid gigantomastia reported, but never to such extreme breast weight. Etiology remains uncertain, and controversy exists in therapeutic modality. According to the literature the most reliable conservative treatment is bromocriptine therapy, but if the condition progresses surgical intervention, in the form of reduction mammoplasty or simple mastectomy, is the treatment of choice.