A total of 250 individuals belonging to 19 different families, identified through established propositi were simultaneously screened for hereditary spherocytosis (SPH), using stringent criteria, and 27 well-known polymorphic genetic marker systems. The segregation analysis indicated that the pattern of inheritance of SPH in these families, being autosomal and dominant, had a 100% penetrance. A statistical analysis, using the LIPED computer program of Ott (1974), revealed the absence of close linkage between SPH and ABO, ACP1, ADA, AK1, C3, DIA2, ESD, FY, GC, GLO1, GM, GPT1, HLA, HPA, JK, K, KM, MNS, P, PGD, PGM1, PGP, PI, and RH. Since an earlier study by other investigators had convincingly suggested a linkage between SPH and GM, we subjected the data to further analysis and found no significant heterogeneity in our recombination values of linkage between SPH and GM, or any of the other informative loci.