Leukopenia occurring after kidney transplantation is a very dangerous condition. It may increase the risk of severe infections which might lead to septicemia or may result in graft loss because the dose of immunosuppressants must be reduced, so it must be diagnosed and treated as soon as possible. The use of recombinant granulocyte colony-stimulating factor (G-CSF) in renal transplant recipients is a new therapeutic approach. This factor is successful in producing a rise in neutrophil count without adverse effect on renal function. We report the successful use of G-CSF in a renal transplant recipient in whom neutropenia developed following pulmonary fungal infection.