Anti-p80-coilin antibody produces a unique pattern of immunofluorescence staining called nuclear dots characterized by the presence of up to six discrete nuclear bodies in interphase cell nuclei. The distribution of this antibody and its clinical relevance have not been established. We studied the prevalence of anti-p80-coilin antibody in the sera from 810 patients with collagen diseases and various skin diseases. Five sera showed the nuclear dot pattern by indirect immunofluorescence on an HEp-2 cell substrate, and reacted by immunoblotting with 80-kDa protein in a nuclear extract from HeLa cells. Four of these sera were from patients with localized scleroderma, and the other was from a patient with primary Raynaud's phenomenon. The patients with localized scleroderma who were positive for anti-p80-coilin antibody had all been classified as having linear scleroderma. They had only one or two lesions, and were negative for antihistone and anti-single-stranded DNA antibodies. Our data indicate that anti-p80-coilin antibody is uncommon in skin diseases: however, this antibody is present in patients with a milder form of linear scleroderma, although the incidence of positivity may not be high.