Thirty patients of either sex (23 M, 7 F) ranging in age between 16 and 36 years, affected of acne vulgaris, were given 20% azelaic acid cream over a period of 6 months. The product, very well tolerated, was significantly and substantially effective for all types of acne, especially for the deep lesions, i.e. nodules and cysts. The rates of improvement obtained indicate that azelaic acid can interfere with various aetiopathogenetic process of acne.