Twenty children with ALL that died in 1959-1960 and 59 children with ALL that died in 1969-1970 were analyzed according to the infections at both their terminal illness and their initial presentations. Despite the availability of more effective agents for pseudomonas and staphylococcus, the pattern of infecting organisms at the terminal illness did not change appreciably in this decade. E. coli, pseudomonas, staphylococcus, and candida were the principal organisms involved as a cause of death. Thirty-five of these 79 patients were febrile when they initially presented, prior to the institution of chemotherapy. Seven of the 35 patients (20%) had proved infections. It appears that the fever in the majority of patients at their initial presentations was noninfectious in origin. In 1969-1970, 13 pulmonary aspirates were performed to aid in the etiological diagnosis of diffuse interstitial pneumonia. Only a single case (8%) of pneumonia due to pneumocystis carinii was detected, and it is our suspicion that the majority of these interstitial pneumonias were viral in origin.