Factors such as the intensification of anti-tumor regimens have enhanced both the depth and length of neutropenia and endorsed severe deficiencies in other immune systems. As a result, the risk of fungal infections has increased substantially. Clinicians should be aware of the possibility to enable a timely diagnosis because many of the problems in the management of invasive fungal infections during neutropenia are as much the consequence of diagnostic short-comings as of lack of therapeutic options. About 7% of all febrile episodes during neutropenia can ultimately be attributed to fungi, Candida and Aspergillus species being the paramount pathogens. Although the data in favor of prophylactic use of antifungals are not convincing, prophylaxis is still recommended in an attempt to protect particularly high-risk patients. Fluconazole still appears a suitable agent in recipients of a bone marrow transplant. Given the paucity of data, reappraisal of the value of empirical antifungal therapy is warranted. Amphotericin B with or without 5-flucytosine is considered the standard therapy for acute candidiasis with fluconazole as an alternative. Amphotericin B is also first-line therapy for invasive aspergillosis in neutropenic patients; lipid-based formulations are recommended for patients who develop nephrotoxity. Recovery of the granulocytes and other immune systems has shown to be of critical importance in the management of all invasive fungal infections.