Immunologic data collected in 11 children (6 girls and 3 boys under fourteen) presenting with linear scleroderma were analysed in a retrospective study: 2 children presented with superficial linear scleroderma, 6 with monomelic scleroderma, 1 with dimelic scleroderma, 1 with the "en coup de sabre" variety associated with dimelic homolateral involvement, and another with "en coup de sabre" scleroderma combined with facial hemiatrophy: Antinuclear antibodies (ANA) were demonstrated in 9/11 cases (i. e. 81 p. 100). The immunofluorescence staining pattern was homogeneous in all nine with a low titer (less than 250 in 5 of them). ANA to single stranded DNA was present in 1/3. The demonstration of ANA in these 9 children was correlated with deep or extensive sclerosis with muscular involvement in 7. But neither the presence nor the titer of ANA were correlated with the subsequent development of osteoarticular sequelae. The level of total complement appeared to be lowered in 3/8 cases. No renal involvement was demonstrated. Blood tests for circulating immune complexes were positive in 4/8 patients. Skin biopsy for direct immunofluorescence was performed in 6 children and demonstrated immunoglobulin deposits in 4: three had IgM fixation on the dermo-epidermal junction, and one had speckled fixation of IgG on epidermal nuclei (this has not previously been reported in localized scleroderma). There data highlight: a--the high frequency of ANA in linear scleroderma.(ABSTRACT TRUNCATED AT 250 WORDS)