We have characterized autoantibodies to nuclear and nucleolar antigens in 112 patients with diffuse scleroderma, CREST syndrome (calcinosis, Raynaud's phenomenon, esophageal dysmotility, sclerodactyly, telangiectasias), scleroderma overlap syndromes, or primary Raynaud's phenomenon by indirect immunofluorescence and radiolabeled immunoprecipitation assays. We noted for the first time that anti-Th RNP antibodies represent a common antibody specificity in scleroderma (occurring in 13% of patients with scleroderma-like illnesses) and that anti-NOR 90 antibodies are quite rare in American patients (none found). In addition, we describe 3 new scleroderma-associated autoantibodies.