Acute invasive aspergillosis (IA) is a devastating disease. Early diagnosis allowing an early treatment may improve the prognosis. However, this goal remains difficult to achieve. When diagnosis is confirmed it is often already too late. Galactomannan antigen detection and DNA detection are under clinical evaluation to improve early diagnosis and management of treatment. Despite antifungal treatment mortality rate is still high. Clinical resistance is more often due to the intensity of immunodepression than to high minimum inhibitory concentrations to antifungal agents; however, resistance to itraconazole may occur in rare instances. Beside acute IA, a chronic form of this infection may be seen as chronic necrotizing pulmonary aspergillosis or chronic invasive sinusitis. Other sites of infection have been described. The patients are immunocompetent or present minor alteration of their immunity or of anatomic structure of the infected site. Among patients with solid organ transplantation, lung and liver transplant patients are at the highest risk of developing IA. A high degree of awareness and efforts for an early diagnosis may participate to improve the poor prognosis.