Introduction and Purpose It has been shown that methoxsalen will enhance the ability of vitiliginous skin to repigment with prolonged exposure to sunlight, the effectiveness varying with the area of skin involved and with the intensity of treatment.1-12Assuming that 100% repigmentation will be attained if treatment is continued long enough and with sufficient intensity, then the question arises as to the permanency of this repigmentation. Must treatment be continued indefinitely, or can it be stopped when the degree of repigmentation is satisfactory and the skin still retain the new pigment? Previous reports have not been concerned with this aspect of the treatment of vitiligo with methoxsalen. The purpose of this study was to answer this practical question within the limits imposed by the period of time methoxsalen has been available for clinical trial and the availability of records and of patients for follow