We performed a retrospective study of the infectious complications in 14 pediatric patients undergoing transplantation with T lymphocyte-depleted bone marrow. The purpose of this study was to document the infectious complications encountered in these patients and to ascertain whether or not they appeared to be more susceptible to any particular infections. It was found that all 14 patients developed infectious complications following transplantation: there were a total of 24 bacterial infections among 11 patients, 21 fungal infections among 11 patients, 2 parasitic infections and 4 viral infections. The viral infections included two cases of infection with cytomegalovirus, one of which manifested as encephalitis and pneumonia, and one case of possible infection with Epstein-Barr virus, which included clinical findings compatible with a lymphoproliferative disorder. These patients were at an increased risk to certain viral infections and particular attention must be paid to the prevention, diagnosis and treatment of these infections.