AimWe review methods and outcomes of a novel parenting intervention, Family Nurture Intervention (FNI), that promotes early mother–infant autonomic co‐regulation and emotional connection in the neonatal intensive care unit (NICU).MethodsFNI involves individualised mother–infant calming sessions combined with maternal emotional expression. Two parallel group randomised controlled trials have evaluated FNI. The first, recruited 150 preterm newborns (26–34 weeks GA) and their mothers, randomised into two groups: FNI (n = 78) and Standard Care (SC) only (n = 72). Dyadic, infant and maternal outcomes were assessed at discharge, 18‐months and 4–5 years corrected age. The second,recruited 135 infants from two level 4 NICUs (FNI n = 66, SC n = 69) with similar outcomes assessed at discharge/term equivalent.ResultsRelative to SC, FNI infants showed improved development and relational health through 5 years. At term age, FNI infants had better autonomic regulation and more mature brain activity and cortical connectivity on EEG. FNI mothers also reported fewer anxiety and depression symptoms post‐discharge. At 18‐month, FNI infants obtained higher cognitive and language scores, and lower attention and social behaviour scores than SC infants.ConclusionsFNI improves the early life development and relational health of high‐risk preterm infants. Further research is important to assess its efficacy in other high‐risk populations and contexts.