The incidence of deep fungal infections has increased in immunocompromised patients. Prompt and reliable diagnosis is crucial for improving the outcome of this life-threatening disease. Non-culture-based diagnostic methods, such as antigen (antibody) detection, are very often used. Detection of 1,3-Beta-D-glucan, a panfungal antigen from fungal cell walls, is one of the new commercially available diagnostic techniques that appear to be useful for patients with suspicion of fungal infection (aspergillosis, candidiasis and infection with rare species). This test can be used directly for early diagnosis of invasive fungal infection or as a tool to identify false positive results of other methods.