Very few studies have been performed to evaluate the efficacy and safety of narrow-band ultraviolet B (NBUVB) therapy in Indian patients with vitiligo and are of small sample size. The purpose of this study is to know the efficacy and safety of NBUVB in 150 vitiligo patients of various age groups. One hundred fifty patients (69 males, 81 females), aged 3-70 years, with vitiligo were treated twice weekly with NBUVB. The starting dose was 250 mJ/cm2 in adults and 150 mJ/cm2 in children, with 20% dose increments at each subsequent visit given for a maximum period of 1 year and were followed-up for 6 months for stability of repigmentation. Statistical methods were employed to establish the relation between the response and the number of exposures, duration of treatment, cumulative dose and the compliance. Analysis of our study showed that a majority of our cases, about 73, achieved 25-75% repigmentation, with an average of 51+/-19 exposures, 51 had <25% repigmentation, with an average of 19+/-11 exposures and 26 had >75% repigmentation, with an average of 74+/-24 exposures. Good response to therapy was directly associated with good compliance, more number of exposures and increasing cumulative dose, which was statistically significant (P<0.01). Adverse effects were minimal. Only three patients developed depigmentation of repigmented sites during follow-up. Our study proves that NBUVB therapy is an effective and safe tool in the management of vitiligo, with good stability of repigmentation and cosmetic appearance.