The familial occurrence of scleroderma is uncommon particularly the limited (CREST) form. We describe 2 families in which such an association occurred. Family pedigree 1 consists of 2 of 3 sisters with CREST scleroderma. Both affected sisters shared HLA types and C4 allotypes including DR5, found more frequently in patients with scleroderma. The unaffected sister did not share this MHC allele. Family pedigree 2 includes a grandmother and grandson with CREST scleroderma as well as a family member with Raynaud's phenomena alone. We conclude that familial occurrence of scleroderma may be associated with shared class II MHC antigens.