Seborrheic dermatitis, characterized by erythema and/or flaking or scaling in areas of high sebaceous activity, affects up to 5% of the US population and often appears in conjunction with other common skin disorders, such as rosacea and acne. Despite ongoing research, its etiology is puzzling. Increased sebaceous and hormonal (androgenic) activity is thought to play a part. Recent evidence suggests an important role for individual susceptibility to irritant metabolites of the skin commensal Malassezia, most probably M globosa. Current approaches thus include agents with antifungal as well as antikeratinizing, and anti-inflammatory activity. Azelaic acid, which has all 3 properties, may be a useful addition to first-line management, which now comprises of topical steroids, the immunosuppressant agents tacrolimus and pimecrolimus, azoles and other antifungals, and keratolytic agents. A recent exploratory study supports the efficacy and safety of azelaic acid 15% gel in seborrheic dermatitis. Azelaic acid may be especially valuable in this application because of its efficacy in treating concomitant rosacea and acne.