Eight-year outcome is reported for three groups of preterm infants with bronchopulmonary dysplasia--group 1 with a birth gestation of less than or equal to 31 weeks receiving supplemental oxygen until the equivalent of 36 weeks' gestation, group 2 of the same gestation receiving supplemental oxygen to 28 days postnatal age but not to 36 weeks gestational age, and group 3 with a gestation of greater than or equal to 32 weeks requiring supplemental oxygen for greater than 28 days--and for an individually matched preterm neonatal comparison group and a term peer comparison group for each bronchopulmonary dysplasia group. The subjects all had parents whose mother tongue was English and were matched for gender, mother's education, and father's socioeconomic status, and in the case of the neonatal comparison groups they also were matched for birth gestation and birth weight. Physical growth and psychoeducational and school performance test scores were similar for the three bronchopulmonary dysplasia study groups with the exception of lower intelligence quotient for those receiving supplemental oxygen for the longest time. Children in groups 1 and 2 had outcome scores similar to those of the neonatal comparison group and significantly below those of their peer comparison groups. On multivariate analysis for group 1 children, 61% of the variance of academic achievement was related to lowest recorded pH, father's socioeconomic status, and lowest recorded PaO2. Compared with the peer groups, the study groups continued to show academic delay when the disabled children were excluded from analysis.(ABSTRACT TRUNCATED AT 250 WORDS)