Vitiligo is a common, idiopathic, acquired, depigmenting disease characterized by loss of normal melanin pigments in the skin. The most interesting treatment methods for extensive vitiligo involve psoralen plus ultraviolet A (PUVA) therapy and ultraviolet (UV)-B phototherapy, particularly narrow-band UV-B. In this randomized and comparative study, we investigated the safety and efficacy of narrow band ultraviolet B as monotherapy and in combination with topical calcipotriol in the treatment of generalized vitiligo. Of the 40 vitiligo patients enrolled in the study, 15 were treated with the calcipotriol plus narrow-band UV-B (NBUVB) and 25 with narrow band UV-B alone. The patients were randomized into two NBUVB treatment groups. The first group, consisting of 24 patients (all male), received only NBUVB treatment; the second group, consisting of 13 patients (all male) applied 0.05% topical calcipotriol ointments twice daily. Both groups were irradiated with NBUVB (311 nm). In the NBUVB group, the percentage of the body surface affected was reduced from 27.21 +/- 10.41 % to 16.25 +/- 8.54% after a mean of 30 treatment sessions. The mean repigmentation percentage was 41.6 +/- 19.4%. In clinical evaluation (moderate and marked/complete response was accepted as an effective treatment), 19 patients (19/24; 79.17%) had clinically good results. In the NBUVB plus calcipotriol group, the percentage of the body surface affected was reduced from 23.35 +/- 6.5% to 13.23 +/- 7.05% after a mean of 30 treatment sessions. The mean repigmentation percentage was 45.01 +/- 19.15%. In clinical evaluation (moderate and marked/complete response was accepted as an effective treatment), 10 patients (10/13; 76.92%) had clinically good results. Statistically significant intragroup reductions from the baseline percentage of the body surface affected were seen at the endpoint of treatment for the two treatment groups (P < 0.001). However, there was no statistically significant difference between the two treatment groups at the end of therapy with respect to the reduction of repigmentation rates (P > 0.05). The present study reconfirmed the efficacy of NBUVB phototherapy in vitiligo. It can be a therapeutic option considered in the management of patients with vitiligo. However, addition of topical calcipotriol to NBUVB did not show any advantage.