Twenty patients with lesions of vitiligo were treated either with % betamethasone valerate (BV) or with % clobetasol propionate (CP) creams and similar control areas with placebo preparations. After 3 months of treatment three of the ten patients treated with BV showed a significant amount of repigmentation only in the steroid-treated areas. Only one of the ten patients treated with CP showed partial repigmentation. Using both light and electron microscopy, histological studies of biopsies taken from control- and steroid-treated areas showed a marked repopulation with functional melanocytes in the repigmenting vitiliginous skin. The melanocytes in these steroid-treated repigmented areas were more dendritic and dopa-positive and, unlike melanocytes in the pigmented margins of untreated areas of vitiligo, contained many melanosomes of normal size, shape and melanization. It appears that both topical corticosteroids are of use for the treatment of selected patients with vitiligo and can induce repigmentation of the skin.