Gigantomastia, or Gravidic macromastia, during pregnancy is a diffuse increase in size of the breasts over and above their physiologic size. It is a rare disorder of undetermined etiology, that may be due to hormonal excess or to hypersensitivity of the target organ. The histologic appearance is of glandular hyperplasia with an increase in connective tissue. Treatment during pregnancy is supportive and pharmacologic; once the patient has delivered surgical treatment is usually indicated. We present herewith a case report of gigantomastia during pregnancy, with a discussion of the treatment and a review of the literature.