New approaches in successful treatment of cancer patients are impaired by increasing incidence of fungal infections with high mortality. Relevant prognostic factors could be identified by numerous trials, such as age, kind and status of disease, intensity of previous chemotherapy, bone marrow transplantation, advanced fungal colonization of gastrointestinal tract. In clinical practice options for prompt and sensitive diagnostics are limited despite of new PCR-techniques. Prophylactic efficiency of polyenes or azoles is proven in high risk patients. Amphotericin B is established for treatment in case of documented or assumed invasive fungal infection. Liposomal preparations are less toxic and at least as effective as conventional amphotericin B in randomized trials.