Several studies demonstrated an increase in time spent within target range when automated oxygen control (AOC) is used. However the effect on clinical outcome remains unclear. We compared clinical outcomes of preterm infants born before and after implementation of AOC as standard of care. In a retrospective pre-post implementation cohort study of outcomes for infants of 24-29 weeks gestational age receiving respiratory support before (2012-2015) and after (2015-2018) implementation of AOC as standard of care were compared. Outcomes of interest were mortality and complications of prematurity, number of ventilation days, and length of stay in the Neonatal Intensive Care Unit (NICU). A total of 588 infants were included (293 pre- vs 295 in the post-implementation cohort), with similar gestational age (27.8 weeks pre- vs 27.6 weeks post-implementation), birth weight (1033 grams vs 1035 grams) and other baseline characteristics. Mortality and rate of prematurity complications were not different between the groups. Length of stay in NICU was not different, but duration of invasive ventilation was shorter in infants who received AOC (6.4 ± 10.1 vs 4.7 ± 8.3, p = 0.029).Conclusion: In this pre-post comparison, the implementation of AOC did not lead to a change in mortality or morbidity during admission. What is Known: • Prolonged and intermittent oxygen saturation deviations are associated with mortality and prematurity-related morbidities. • Automated oxygen controllers can increase the time spent within oxygen saturation target range. What is New: • Implementation of automated oxygen control as standard of care did not lead to a change in mortality or morbidity during admission. • In the period after implementation of automated oxygen control, there was a shift toward more non-invasive ventilation.