The authors report a case of congenital dyserythropoieses, type II, the diagnosis of which was made in a young 15 year old girl with anemia, sub-clinical jaundice and splenomegaly. The following three criteria were found: erythroblastic hyperplasia with a high percentage of binuclear cells, a double peripheral red cell membrane under the electron microscope and a positive Ham-Dacle test. An isotopic study showed a double process or erythropoiesis which was inefficacious and peripheral hemolysis. In connection with this case, the authors then recall the main characteristics of the three types of congenital dyserythropoiesis. The origin and consequences of the peripheral membrane excess of the erythroblasts characteristic of type II are then discussed.