Background: Vitiligo is an acquired hypomelanotic disorder characterized by decrease Bcl2(antiapoptotic marker) immunoexpression in melanocytes of vitiliginous lesions in untreatedpatients. The mainstay treatment for vitiligo is PUVA. BB-UVA was found to produce tanning ofvitiliginous lesions. Aim of work: To compare the efficacy of PUVA versus BB-UVA in the treatment of vitiligo andwhether BB-UVA can be an alternative line of therapy. The study also aimed at comparing theeffect of PUVA versus BB-UVA on the apoptosis of melanocytes and keratinocytes in vitiligopatients and whether prevention of apoptosis is a possible mechanism of clinical improvement.Patients and Methods: This prospective randomized controlled single blinded comparativeclinical trial included 45 patients with generalized vitiligo who were randomly divided into threeequal groups (15 patients in each group); group A receiving UVA 15 J/cm2/session, group Breceiving UVA 10J/cm2/session and group C receiving PUVA. The patients received threesessions/week for five months (60 sessions). Patients were evaluated clinically and byimmunoexpression of Bcl2 in melanocytes and keratinocytes in skin biopsies.Results: The extent of clinical response was significantly higher in patients receiving PUVA thanthe other two groups at mid therapy (30 sessions). At the end of the study (60 sessions), theclinical response was significantly higher in patients receiving PUVA than patients receiving UVA10 J /cm2 only. Phototoxic reactions were significantly higher in patients receiving PUVA.Immunoexpression of Bcl2 in melanocytes and keratinocytes was significantly higher at midtherapy than pre therapy in all the groups regardless of the type of therapy. Also, there was nosignificant correlation between the extent of response and the difference in Bcl2immunoexpression pre and mid therapy in the three groups.Conclusion: BB-UVA produces mainly tanning of the lesions, and only at higher doses the extentof response is comparable to PUVA. Irradiance of vitiliginous lesions by UVA, with or withoutpsoralen intake, leads to antiapoptotic effect on melanocytes and keratinocytes. However, thiseffect does not correlate with the clinical improvement of vitiligo lesions.