Fifteen diabetic families and fifty non related diabetic patients were studied for their HLA antigen pattern. The patient group was compared to controls matched to compensate for ethnic variations. In this group the data analysis revealed a decrease in HLA-A1 as opposed to increased HLA-A2 frequency, both of no statistical significance; HLA-Aw26 was found significantly increased (p less than .0005; corrected p less than .015); HLA-B8 was found to be increased (p = ,0025) but not significantly after correction (p = .075). Family analysis revealed that whenever B8 was present it was inherited to the affected sib only. Where B8 was not present, the same haplotypes were shared by healthy and affected sibs. Bw16 although not significantly increased, was found in all patients but one, when part of the family pattern, although non affected sibs shared it as well,