Chronic lung disease that requires prolonged oxygen therapy commonly complicates the recovery of extremely low-birth-weight infants (less than 1000 g). We report follow-up data through 18.5 +/- 0.9 (mean +/- SEM) months of age in 30 extremely low-birth-weight infants (birth weight, 783 +/- 24 g; gestational age, 26.0 +/- 0.3 weeks) who were discharged home receiving supplemental oxygen. Oxygen was prescribed to maintain arterial oxygen saturation at 95% or greater. At discharge, postconceptional age was 40.5 +/- 0.6 weeks, and weight was 2220 +/- 50 g. Duration of home oxygen therapy was 4.5 +/- 0.5 months. The mean weight percentile increased from less than 5 to 23 between discharge and the last follow-up. All infants survived; only 6 required hospitalization for acute medical illnesses. We conclude that carefully supervised home oxygen therapy permits the safe early discharge of selected extremely low-birth-weight infants with chronic lung disease.