Abstract: Blood and marrow transplantation (BMT) is increasingly used to treat malignant and nonmalignant diseases. Despite significant advances in the management of transplant recipients, however, fungal infections remain important life-threatening complications of BMT. Over the past two decades, the incidence of fungal infections in this population has continued to rise. Several factors predispose BMT recipients to invasive fungal infections. These include but are not limited to use of intensive myeloablative chemotherapy and radiation therapy combined with prolonged granulocytopenia; development of acute and chronic graft-versus-host disease; administration of immunosuppressive therapy, particularly using corticosteroids; use of central venous catheters; and prolonged impairment of cell-mediated immunity secondary to the underlying disease and post-transplant immunodeficiency. Environmental factors also play a key part in the pathogenesis of fungal infections. Therefore, infection-control measures are critical to the prevention of such infections. In addition, although Candida and Aspergillus species are still the major culprits, other opportunistic fungi have emerged in recent years.