Clobetasol-17-propionate, the most potent of currently available topical steroids as predicted by the vasoconstrictor assay, has just been approved in the United States. In psoriasis, it has proved significantly more effective than class II steroids and as or more effective than the only marketed class I steroid. In the more steroid-responsive eczemas, the superior efficacy of clobetasol is also apparent, but less striking. Clobetasol prolongs remission rates, making intermittent treatment schedules feasible and minimizing inherent potential steroid side effects. Clobetasol may also be useful in the treatment of a myriad of other skin conditions. A review of the pharmacology, efficacy, and side effects of this addition to our dermatologic armamentarium is presented here.