A case of thyrotoxicosis due to the occupational exposure to cosmetics in a 35-year-old beautician is reported. The hormonal pattern was consistent with exogenous thyroid hormone administration, but not with iodine hyperthyroidism. The patient denied she was using thyroid hormones; also, she lacked the typical features of patients with thyrotoxicosis factitia. Her occupational history was carefully reviewed: A heavy exposure of the unprotected skin to cosmetic creams containing iodine, thyroid hormones, and thyroid extracts had occurred in the previous months. The patient was advised to refrain from the exposure, and a persistent remission of thyrotoxicosis was observed thereafter. This case suggests that percutaneous absorption of thyromimetic substances though never described before, may occur in an occupational setting. We advise that such cosmetics be handled with care, not only by patients with thyroid disease but by euthyroid subjects as well; close medical surveillance over the use of such preparations seems appropriate.