OBJECTIVE: To characterise the actuarial day-by-day survival of premature infants in a geographically defined population. SETTING: 10 Neonatal Intensive Care Units (NICUs) in New South Wales (NSW) and Australian Capital Territory (ACT), Australia. DESIGN: Retrospective analysis of prospectively collected data as part of NICUs' data collection in NSW and ACT. SUBJECTS: Premature infants born at 22(+0) to 31(+6) weeks' gestation between January 1997 and December 2006 and admitted to one of the 10 NICUs in NSW and ACT. OUTCOME: Actuarial day-by-day survival to discharge from NICU. RESULTS: Survival to discharge after initiation of neonatal intensive care ranges from 30.0% at 23 weeks' gestation to 98.8% at 31 weeks. Actuarial day-by-day survival increased across all gestations. This improvement was most notable among the babies who were born <26 weeks gestation. CONCLUSION: Preterm infants who survive the first few postnatal days have considerable chances of long-term survival. It is important to revise the information stored regarding chances of survival so it covers chances at regular intervals, especially after the first few days of life.