Narrow-band ultraviolet B (NB-UVB) is considered the most effective and safe initial treatment for moderate-to-severe vitiligo but phototoxicity and possible carcinogenicity are the reported side effects. Ultraviolet A1 (UVA1) phototherapy has overlapping biological effects to NB-UVB and is relatively free of side effects associated with other phototherapy regimens. Forty patients with vitiligo were included in this prospective, randomized controlled comparative clinical trial. Twenty patients received NB-UVB and 20 received UVA1 three times weekly for 12 weeks. The UVA1 group was divided into two subgroups. Ten patients received moderate and 10 received low dose of UVA1. Serum samples were collected before and after 36 sessions to assess soluble interleukin 2 receptor level. Patients were clinically evaluated before therapy then monthly according to Vitiligo Area Scoring Index (VASI) and Vitiligo European Task Force (VETF) scores. In addition, extent of response was determined by a blinded dermatologist comparing before and after therapy photographs. Pattern of response and side effects were recorded. NB-UVB was superior to UVA1 with a significant difference in blinded dermatological assessment (P<0.001), percentage change in VASI score (P<0.001) and percentage change in VETF area score (P=0.001). No significant difference in side effects was observed between both groups. Comparing UVA1 subgroups, better response in moderate-dose group was found as regard to percentage change in VASI (P<0.001) and percentage change in VETF area score (P=0.001), while no significant difference was found in blinded dermatological assessment (P=0.121). NB-UVB phototherapy remains to be an effective and safe therapeutic option in vitiligo. Response to UVA1 in vitiligo seems to be dose dependent and seems to be of limited value in treatment of vitiligo as a monotherapy. Further studies combining it with other lines of therapy such as systemic steroids may prove beneficial.