Aims: To test the effectiveness of a home based developmental education interv ention in improving outcome at 5 years for very preterm infants. Methods: The Av on Premature Infant Project (APIP) is a randomised controlled trial in which the parents of 284 babies born < 33 weeks gestational age received a developmental education programme, a social support intervention, or standard care. A term ref erence population was also recruited. This study reports outcomes at 5 years (me an age 58 months 15 days) for 187 (66%) of these children without disability. O utcomes were assessed using the British Ability Scales II for cognitive developm ent, the Movement ABC for motor impairment, and the Child Behavior Checklist for behavioural problems. Results: Preterm infants showed poorer cognitive performa nce than their term peers. Mean (SD) general conceptual ability (GCA) scores wer e: Portage 99.2 (15.7); parent adviser 100.3 (14.8); preterm control 101.1 (15.0 ); term reference 107.2 (13.4). There were no significant differences between pr eterm groups in GCA scores indicating no effect of either intervention. Similarl y, there was no significant effect of intervention on behavioural or motor outco mes. Further analyses, in which outcome data were adjusted for social factors, d id not reveal any differences between the three preterm groups or by sub groups classified by a range of perinatal variables. Conclusion: The small adv antage shown at 2 years of age is no longer detectable at 5 years. These results question the effectiveness of early intervention in enhancing cognitive, behavi oural, and motor function at 5 years. Aims: To test the effectiveness of a home based developmental education interv ention in improving outcome at 5 years for very preterm infants. Methods: The Av on Premature Infant Project (APIP) is a randomized controlled trial of which the the parents of 284 babies born < 33 weeks gestational age received a developmental education program, a social support intervention, or standard care. A term ref erence population was also recruited. This study reports outcomes at 5 years (me an age 58 months 15 days) for 187 (66%) of these children without disability. O utcomes were assessed using the British Ability Scales II for cognitive development ent, the Movement ABC for motor impairment, and the Child Behavior Checklist for behavioral problems. Results: Preterm infants showed poorer cognitive performa nce than their term peers (SD) general conceptual ability (GCA) scores wer e: Portage 99.2 (15.7); parent adviser 100.3 (14.8); preterm control 101.1 (15.0); term reference 107.2 (13.4). Th Similar to y, there was no significant effect of intervention on behavioral or motor outco mes. Further analyzes, in which outcome data were adjusted for social factors, d id not reveal any differences between the three preterm groups or by sub groups classified by a range of perinatal variables. Conclusion: The small adv antage shown at 2 years of age is no longer detectable at 5 years. These results question the effectiveness of early intervention in enhancing cognitive, behavi oural, and motor function at 5 years.