Invasive aspergillosis is a devastating infection affecting severely immunocompromised patients, most frequently with hematologic malignancies. In recent years, a surge in the incidence of invasive aspergillosis has been reported in critically ill patients without the classical risk factors. The mortality of the disease is equally high in the group of intensive care unit (ICU) patients, while the clinical signs and symptoms are nonspecific and the diagnosis remains a challenge. New noninvasive diagnostic methods in combination with better tolerated antifungal drugs aim for early diagnosis and improved prognosis of invasive aspergillosis. In this review, we discuss the epidemiology, the diagnostic strategy and algorithms, and the therapeutic choices of this severe infection in critically ill patients.