Five patients with lichen planus were treated with retinoic acid, and all 5 patients showed almost complete resolution of skin lesions within 1 month. In 4 of the cases treatment started 2–3 months after the beginning of the disease. With retinoic acid by mouth, relief of pruritus and flattening of papules was achieved leaving only residual pigmentation. Hyperkeratotic lesions improved only when retinoic acid was applied topically. The effects of treatment on the duration of the disease are discussed.