Our experience, accumulated over the past years, can confirm that topical azelaic acid, applied for long periods, does not give rise to toxic or allergic reactions. In this study we report the results obtained in the treatment of all types of acne (comedo or papulo-pustular acne). Azelaic acid cream showed a progressive and significant beneficial effect in all the patients who regularly followed the therapeutic program. Topically applied azelaic acid alone can yield clinically relevant improvement rates also in the treatment of inflammatory acne.