BACKGROUND Targeted ultraviolet (UV) phototherapy is a recent addition to the therapeutic armamentarium for the treatment of localized psoriasis. Topical psoralens enhance the therapeutic effects of UV-based treatment for various dermatoses, but have never been used in conjunction with targeted UVB. OBJECTIVE To compare the efficacy of targeted narrowband UVB phototherapy (NB-UVB) alone with that of the combination of 0.1% 8-methoxypsoralen cream and targeted NB-UVB phototherapy (8-MOP/NB-UVB) for the treatment of plaque-type psoriasis. METHODS Two areas within the same lesion of stable psoriasis were randomized to receive either targeted NB-UVB alone or 8-MOP/NB-UVB. Fluences of UVB delivered were held constant at four minimal erythema doses. The treatments were continued until lesions cleared or 12 treatments. Follow-ups were done until lesional scores returned to 50% of the baseline values. RESULTS Ten patients completed this study. Four lesions were cleared by 8-MOP/NB-UVB while three were cleared by NB-UVB alone. The improvement in disease activity as reflected by psoriasis severity index score during treatment was statistically significantly better in the combination group (P=0.005). Mean remission time of lesions which were cleared by 8-MOP/NB-UVB was 8 weeks while that for lesions that were cleared by NB-UVB alone was 4.67 weeks. CONCLUSIONS We concluded that addition of 0.1% 8-MOP cream to targeted narrowband UVB significantly enhances the therapeutic effects of the light treatment without increasing the incidence of adverse effects.