There are a few reports documenting proton pump inhibitor-induced lupus erythematosus. Here, we present a 57-year-old woman treated with lansoprazole for chronic duodenitis, who subsequently developed extensive annular erythematous lesions on the skin. Laboratory examination revealed anti-Ro antibodies, leucopoenia and decreased C3 complement level. The skin histology demonstrated vacuolar degeneration of the epidermal basal layer and lymphocytic perivascular infiltrate in the dermis. Subacute cutaneous lupus erythematosus was diagnosed, possibly related to lansoprazole. The drug was discontinued and the patient received prednisone and ranitidine. Complete clearance of skin lesions was noted within 4 weeks and no relapse occurred upon corticosteroid discontinuation.