Previously, we have reported in 1990 that 35% of carmustine treated patients (6 of 17) who survived childhood brain tumors died of pulmonary fibrosis between 2 and 13 years after treatment. In addition, 8 patients studied in 1989 (13 to 17 years post treatment), had physiologic and biopsy or radiologic evidence of pulmonary fibrosis. We now report 3 more years of follow-up on these patients. Between 1989 and 1992, two more patients have died of pulmonary fibrosis, giving an overall mortality of 47%. Of the eight patients who died of pulmonary fibrosis, the median age at treatment was 2.5 years, whereas the nine long-term survivors had a median age at treatment of 10 years. All five patients treated below the age of 5 years have died of lung fibrosis. Analysis by the standard survival curve method indicated that patients treated at an age less than 6 years were more likely to die than those treated at an age older than 7 years (p=0.03). Of the nine survivors, seven were observed over 3 more years. There was a gradual decline in mean forced vital capacity from 55% predicted (range, 44 to 81) to 51% predicted (range, 41 to 72) and total lung capacity fell from 65% predicted (range, 51 to 89) to 57% predicted (range, 47 to 77).