Forty cases of lichen planus actinicus (l.p. a.) are reviewed. L. p. a. primarily attacks children and young adults of oriental extraction. Three clinical types are described: a pigmented, a dyschromic and a granuloma annulare type. Kimmig''s light-band spectroscopic examination was positive in 10 out of 12 cases examined. The importance of light as a contributory detrimental agent is stressed. Histological findings corresponded only partly to that of classical lichen planus. In some cases there was a resemblance to lupus erythematodes discoides, actinic dermatitis and irradiation dermatitis.