With its increasing importance as a human pathogen, the study of the <i>Aspergillus fumigatus</i> genome became a priority. Recent studies show that the frequency of aspergillosis invasive disease has risen approximately 14-fold over the past 12 years. Invasive aspergillosis has overtaken candidiasis as the most frequent fungal infection in the world. People at risk are transplant recipients, patients with HIV/AIDS, with chronic granulomatous disease, with severe combined immunodeficiency, among others. Fungi of the genus <i>Aspergillus</i> are also pathogenic to other mammals. Examples of veterinary diseases include pulmonary and airsac infections in birds (particularly in chicks and turkey poults), abortion and mastitis in domestic livestock, such as cattle, and guttural pouch aspergillosis in horses. <p>The <i>Aspergillus fumigatus</i> genome is estimated to be 30 Mb, organized in 8 chromosomes. The sequencing and analysis of the <i>Aspergillus fumigatus</i> genome will contribute to the understanding of the biology of this important human and animal pathogen, and the identification of the molecular pathology of aspergillosis.