The ultrastructure of the red blood cell membrane and its surfaces is characterized by freeze-etching and stereoscan electron microscopy for the normal red blood cell and cells from patients with sickle cell anemia, hemoglobinopathy CC, and Heinz body hemolytic anemia. The external surface, intramembrane surfaces, and the internal surface of the normal red blood cell are described and the alterations of membranocytoplasmic relationships in the hemoglobinopathies studied are shown.