Invasive fungal infections have become increasingly common in patients with hematologic malignancies, especially in those at high risk with prolonged neutropenia and graft versus host disease after allogeneic stem cell transplantation, and are associated with significant morbidity, mortality, and cost. New diagnostic techniques and therapeutic agents have emerged recently to assist in the management of these infections. The galactomannan assay in association with routine clinical and radiologic screening may assist in the early diagnosis of invasive aspergillosis such that therapy may be initiated early. Also, several new antifungal agents have become available, allowing the practitioner more options in the prevention and treatment of fungal infections. New antifungal agents such as the lipid amphotericin B products, voriconazole, and the echinocandins appear to be safer to use than conventional amphotericin B. Voriconazole also has shown superiority to conventional amphotericin B in the treatment of invasive aspergillosis, and its well absorbed oral formulation makes it an excellent treatment to complete therapy as an outpatient. All these therapeutic options allow physicians to tailor antifungal therapy to the individual patient based on response and toxicity to prevent or treat invasive fungal infections. There are several new antifungal agents in development, and future studies will evaluate combination therapies to determine safety and efficacy.