AbstractWhen HeLa cells were used as the substrate for detection by the indirect immunofluorescence method, antinuclear antibodies were demonstrated in 16 of 22 (72.7%) sera from patients with localized scleroderma. When mouse kidney sections were used, the positive rate for antinuclear antibodies was 50% (11 of 22). In the 3 subgroups of localized scleroderma, frequencies of anti‐nuclear antibodies on HeLa cells were as follows: morphea, 50% (2 of 4), generalized morphea, 100% (6 of 6), linear scleroderma, 67% (8 of 12). Antibodies to centromere, Scl‐70, nuclear RNP, Sm, and SS‐B antigens were not detected in any patient with localized scleroderma. The high frequency of antinuclear antibodies in localized scleroderma sera suggests that localized scleroderma is a disease which, though different from diffuse scleroderma, also involves an immunologic abnormality.