Among emerging and re-emerging infectious diseases, influenza constitutes one of the major threats to mankind. In this review series epidemiologic, virologic and pathologic concerns raised by infections of humans with avian influenza virus A/H5N1 as well as treatment options are discussed. The third part discusses therapeutic options. Neuraminidase (NA) inhibitors are the most promising agents despite uncertainty about efficacy. Dosage increase, prolonged treatment or combination therapies may increase treatment efficacy and/or inhibit resistance formation. Immune system dysregulation contributes to H5N1 disease. Although current evidence does not support the use of anti-inflammatory drugs beneficial effects cannot be excluded at later disease stages.