Background: UV phototherapy has recently demonstrated high levels of efficacy and tolerability for treating a variety of inflammatory skin diseases. Objective: The purpose of the present study was to evaluate the efficacy of narrow band versus broad band in the treatment of pityriasis rosea. Methods: Twenty patients (12 female __ampersandsignamp; 8 male) with extensive pityriasis rosea type III __ampersandsignamp; IV were participated in the study. Their ages ranged between 18 and 35 years.The right half of the body of each patient was irradiated with NB-UVB ,while left side of each patient is exposed to broadband BB-UVB for 3 times alternatively per week until clearing of lesions or for 6 weeks. The rate of clearing was monitored by estimating the pityriasis rosea severity (PRSS) score and the pruritus score. Results: The extent of disease (PRSS) for Rt side decreased from (34.30__ampersandsignplusmn;10.16vs. 10.50__ampersandsignplusmn;7.00, respectively__ampersandsignlt;0.05) while for Lt side (35.90__ampersandsignplusmn;10.31.vs. 16.00__ampersandsignplusmn;9.06). The percentage of reduction in intensity of puritis were 53%, 49%, for NBUVB side and BBUVB side respectively. Conclusion: This study shows that NBUVB was more effective than BBUVB in reduction of PRSS and the degree of pruritus in pityriasis rosea.