A group of patients has been identified with cutaneous necrotizing venulitis (vasculitis). These patients, some with concomitant connective tissue disorders, have skin lesions that separate them from the arteritis commonly described as rheumatoid vasculitis. HLA typing has been performed on 31 of these unrelated patients with cutaneous necrotizing venulitis, including 19 with associated chronic disorders. The antigen pair All,BW35 was found in 5 of these 19 patients and in 11 of 346 controls. This difference in frequency is statistically significant. Because HLA genes appear to be linked to immune response genes, these data suggest that such genes may exist in patients with this form of cutaneous necrotizing venulitis with associated connective tissue disease.