The spectrum of infectious complications in neutropenic patients after stem cell or bone marrow transplant is not very different from that seen in other neutropenic patients, with the possible exception of fungal infections. The prevention and therapy of these infections remain a major challenge. The management of neutropenic patients after stem cell or bone marrow transplant has markedly benefited from the development of new antiviral agents and the use of granulocyte/macrophage colony stimulating factors.