Of 1,203 patients who received radiation treatment for acne vulgaris between 1940 and 1968, 302 patients were recalled and examined, 121 at Geisinger Medical Center and the remainder by their local physicians. Radiation records were reviewed on all patients. Lead-rubber and cones had been used as shielding. Mean age at the time of exposure was 21 years and mean total exposure was 692 R. Palpable nodular thyroid disease was found in eight patients (2.6%). Of these, thyroid carcinoma was detected in two patients (0.66%). Although the number of patients examined was small, the incidence of carcinomas was unexpectedly high. We conclude that follow-up examination is worthwhile for patients previously treated by irradiation for acne vulgaris.