Radiation-induced acne is a rare, clinically and pathogenetically ill-defined acneiform dermatosis with special features that may occur in irradiated skin areas especially after high doses of deeply penetrating radiation. We report on a patient with an oropharyngeal carcinoma who developed severe radiation-induced acne including comedones and cysts as well as few inflammatory papules and pustules in a skin area irradiated with up to 63 gray of a 6 MeV photon beam. Acnegenic drugs may precipitate the disease; our patient was on longterm therapy with carbamazepine whose acnegenic potency is less well documented than that of testosterone or glucocorticoids. Treatment of radiation-induced acne is comedolytic; topical retinoids are especially valuable.