SUMMARYSuperficial radiotherapy in benign dermatoses, and in acne vulgaris in particular, has long been a subject of controversy among members of the medical profession. Those who favour it are convinced of its therapeutic value and safety if used correctly. Those who condemn it question its efficacy and stress its carcinogenic and leukaemogenic potential. These opposing views are discussed, and the result of investigations to determine the radiation received by the thyroid gland during superficial radiotherapy for acne are presented. For the sake of uniformity all radiation dosage is stated in rads.