Lichen sclerosus (LS) is associated with autoimmune disease in female children and adults. In adult women, there are antibody and T-cell responses to proteins in the basement membrane zone (BMZ). The aim of this study was to investigate reactivity to the BMZ in girls with LS. Nine girls with vulval LS were studied clinically and serologically. The presence of circulating BMZ autoantibodies was investigated. Autoimmunity was assessed by personal and family history of autoimmune diseases and autoantibodies. We detected circulating BMZ antibodies in four of the nine children, all with IgG responses. Three patients were positive by indirect immunofluorescence, one had a positive ELISA reaction to bullous pemphigoid antigen (BP)180, and three had a positive reaction on BP180 immunoblots. There was no association with autoimmune disease or clinical features. To our knowledge, this is the first study to find BMZ autoantibodies in children with vulval LS. The autoantibodies were directed at BP180 and were exclusively of the IgG class.