Acne, one of the most common skin problems in dermatological practice, is a condition that affects not only adolescents but also adults. While approximately 80% of cases occurring in adulthood are persistent from teenage years, around 20% are described as 'late-onset' disease, appearing for the first time in adulthood. The disease can be triggered by hormonal changes (including a change from one contraceptive to another), or it can be induced by certain non hormonal medications, emotional stress, and various underlying diseases such as polycystic ovary syndrome. In many cases acne becomes a chronic skin condition with undulating activity, including improvement and relapse phases, and is often experienced as a major psychological burden. It is, therefore, even more important to provide an effective as well as a safe and tolerable treatment. The spectrum of topical acne treatments has expanded substantially in recent years and various topical medications are available, ranging from azelaic acid, antibiotics, retinoids and benzoyl peroxide to several fixed combinations of these active compounds. The following case collection illustrates how 15% azelaic acid gel, as a well-established monotherapy, can be successfully employed to treat mild-to-moderate forms of adult female acne.