We report an infant with exogenous Cushing syndrome after being treated for 2 months with a potent topical corticosteroid via the mother's application of topical clobetasol for diaper rash without a prescription. We emphasize that potent topical steroids should be used with great caution, especially when used under occlusion (e.g., diaper area) and that parents should be warned about potential side effects of these medications, particularly when used in infants.