The aim of this study was to describe principal problems and to analyse transport times, stabilizing procedures, adverse events during transfer, outcome, effectiveness and the care of infants transferred by air from district general hospitals and maternity homes to a central hospital. Transfer times, equipment adverse events and clinical deterioration were recorded as they occurred. Data regarding clinical problems, diagnoses and outcome were collected retrospectively from hospital records. During the study period (1984-95) 275 infants (267 transports) were transferred by fixed-wing aircraft (233) or helicopter (34). Median time from request of transfer to arrival of the transport team (usually a neonatal nurse and a paediatrician) was 120 min, median stabilizing time 60 min. Ninety-six infants (35%) were intubated, 62 (22.5%) by the transport team. During 34 transports (12.7%), equipment-related adverse events occurred making six infants worse. Ten more infants deteriorated during transit. A significant correlation between birthweight and after-transfer temperature was recorded. After-transfer temperature for very low birthweight (<1500 g, VLBW) infants was significantly higher when the transport team attended the delivery than when they did not (35.9 degrees C vs 34.7 degrees C). All nine infants (3.2%) with after-transfer temperature <34.0 degrees C died, 15 infants (5.5%) died within 24 h after transfer and 20 (7.3%) died later. Adjusted OR for death among transported versus in utero transferred VLBW infants was 3.8 (1.4-10.4). Every effort should be taken to transfer VLBW infants in utero. If preterm deliveries at 26-28 weeks of gestation at district general hospitals is unavoidable, an early request for the neonatal transport team to be there at delivery is advisable. Transport of very immature infants <26 weeks gestational age is not recommended. An outreach educational program ("Team Pink Newborn") has been created. Staff training to combat hypothermia and regular inspection and control of the transport equipment by three neonatal intensive care nurses has now been implemented.