SUMMARYThe potency of topical corticosteroids has been evaluated using a recently described test which measures both their vasoconstrictor and anti‐inflammatory activities. Betamethasone valerate, fluocinolone acetonide and triamcinolone acetonide creams were found to have practically the same potency. They were all superior to a combination of fluocortolone caproate and fluocortolone trimethylacetate cream. A remarkable difference was observed between the vasoconstrictor and the anti‐inflammatory activity of the latter preparation. The significance of this finding is discus