The diagnosis of bronchopulmonary dysplasia (BPD) is frequently used as an identifier of children at risk for long term developmental difficulty. However it is possible that BPD only appears to be a risk factor because it clusters in very low birth weight survivors and serves as a proxy for other risk factors. To determine the relationship of BPD (oxygen dependence > 30 days) and school difficulty at 7- 9 years, we reviewed the number of days on oxygen during the nursery course and the school age outcome of ELBW (≤1000 g) infants admitted to the Vanderbilt University Hospital (VUH) from July 1982-July 1989 and enrolled in the follow-up program. Data are available on 81% of eligible survivors (n=212; mean birth weight= 828 ± 24g, range 460-1000; mean gestational age 27 ± 2.0 wks, range 23-37). Parents were interviewed to assess presence or absence of school difficulty defined as need for special education resources or grade retention. IQ testing with the Wechsler Intelligence Scale for Children was performed on a representative sample of the group (n= 76). We found that 72% (153/212)of the ELBW survivors have experienced school difficulty, but this was not related to their BPD status (P=0.3, Fisher's exact test). School difficulty appeared in 74%(117/158) of the BPD group and 66% (36/54) of the non-BPD group. Conversely, in the group of children without school difficulty, 78% (46/59) had BPD. Additionally, IQ test results were correlated with total numbers of days on oxygen. Although a negative correlation was found between IQ scores and duration of oxygen dependence (r = -.24, p<.05), this analysis suggests oxygen dependence alone explains only a small percent of variance (4%). We conclude that in our sample of ELBW infants, the risk for school difficulty is independent of oxygen use per se or duration of oxygen treatment during the nursery course. It is likely that risk for long term developmental difficulty is related to the multifaceted problems of extreme immaturity rather than pulmonary disease.