Organ transplant recipients, on long-term immunosuppressive therapy, are at increased risk for life threatening opportunistic fungal infections. The incidence of these rare infections has increased considerably over the last decade. In order to evaluate the incidence of invasive fungal infections and to identify the most common fungal pathogens, we conducted a multi-center retrospective study on 5424 ESRD cases undergone living kidney transplantation in four transplant centers between 1984 and 2008. Data gathered included age, sex, date of transplantation, total number of operations, immunosuppressive regimen, graft rejection episodes, date of diagnosis, fungal pathogen, organs affected by infection, treatment and patient's outcome. Invasive fungal infections developed in 21 recipients (0.35%), 18 male and 3 female. Their immunosuppression was cyclosporine based. The mean age of patients was 49±10 (ranged from 32 to 67) years. Diagnosis was made by radiological findings, positive blood or bronchoalveolar lavage (BAL) cultures and tissue biopsies. Mucormycosis was the most common cause of opportunistic fungal infections in population studied (n = 10), followed by aspergillosis (n = 3), disseminated candidiasis (N = 4), nocardiosis (N = 2) and histoplasmosis (n = 1). Pulmonary involvement was dominant (50%). Renal transplant recipients with invasive fungal infection did not experience more graft loss. The treatment modalities were successful in only 9 patients and the rest died of disseminated infection. In our large series of kidney transplant recipients, mucormycosis was found to be the most common cause of invasive fungal infection. Prompt diagnosis and treatment are necessary to avoid the life threatening complications and may greatly improve prognosis.