A normal 46, XX karyotype was demonstrated in an Indian woman who has 2 approximately equal populations of red cells and of leucocytes. She also has skin mosaicism. She is a normal female and has borne 4 healthy children. The ABO, Ss, Rh and Fy groups of her 2 red cell populations differed, but both were Le(a+b-) although she is a secretor of B and H substances. The relationship between this and the 7 examples of dispermywith blood group mosaicism reported in the literature is discussed briefly