Major advances in anticancer treatment have contributed to an increased frequency of severe fungal infections in patients with neoplastic diseases. Neutropenia remains the most important among the predisposing factors related to the malignancy or its treatment. Most fungal infections are caused by the commonly recognized opportunistic fungi Candida spp and Aspergillus spp, and the pathogenic fungi Cryptococcus neoformans, Histoplasma capsulatum, Coccidiodes immitis, and less often by Blastomyces dermatidis. However, recently newer pathogens such as Pheohyphomycetes, Hyalohyphomycetes, Zygomycetes and other fungi of emerging importance such as Torulopsis glabrata, Trichosporon beigelii, Malassezia spp, Saccharomyces spp, Hansenula spp, Rhodotorula spp, and Geotrichum candidum have appeared as significant causes of infection in this patient population. The increasing frequency of fungal infections is of great concern because of the difficulties in diagnosis and treatment. Amphotericin B remains the mainstay of antifungal treatment despite its toxicity and limited efficacy. Liposomal Amphotericin B may be more effective and less toxic. The activity of the azoles in immunocompromised patients is low. New azoles such as fluconazole and itraconazole may show future promise. The availability of the new granulocyte colony stimulating factors which can shorten the duration of neutropenia could represent a significant improvement in the management of fungal infections in cancer patients. As a preventive measure, the invasive procedures that predispose to infections should be done only when absolutely necessary and frequent handwashing by hospital personnel remains an effective prophylactic procedure.