Invasive aspergillosis causes a markable part of infection-associated morbidity and mortality in immunocompromised patients. For none of hitherto available antimycotic agents a significant superiority could be demonstrated which all are characterised by unsatisfactory response rates. The newly developed and approved voriconazole is characterized by broad antifungal activity against numerous yeasts and filamentous fungi, including Aspergillus species. Voriconazole is available for intravenous administration and shows excellent bioavailability with oral application. The profile of toxicity is typical for azoles with the particularity of causing obviously substance-specific transient, benign visual disturbances. In clinical studies could be shown that voriconazole is significantly superior to the previous antimycotic standard, amphotericin B, with regard to therapy response and survival. In patients with invasive aspergillosis the therapy response with voriconazole is about 45% even in otherwise therapy-resistant cases.