Background & Objectives: Resistance Strains of propionibacterium acnes is one of the most growing problems in acne treatment. Azelaic acid, due to the lack of bacterial resistance, could be a useful alternative in topical treatment of acne. The purpose of this study was to investigate the therapeutic effects and side effects of azelaic acid and its comparison with topical clindamycin in the treatment of acne.

 Methods: This randomized clinical trial study was performed on 100 patients with mild acne. The patients were divided in to two groups. One group was treated with azelaic acid 20% cream and the other one was treated with Dalacin 1% gel twice daily for 4 weeks.

 Results: Both drugs Produced significant reduction in inflammatory Lesions (for azelaic acid p=0/000 and for clindamycin p=0/000) and noninflammatory lesions (for azelaic acid P=0/001 for clindamycin p=0/033). Comparing the mean of decrease in inflammatory and noninflammatory lesions, there was not a significant difference between two groups (of Papule and Pustule P=0/864 of comedons P=0/239). So the efficacy of these two drugs was same. In comparing the sideffects, erythem was more common in azelaic acid users significantly (p=0/031) and skin dryness was more Common in clindamycin users significantly (p=0/000).

 Conclusion: Azelaic acid 20% cream as effective as clindamycin gel 1% in the treatment of mild acne.