This paper reports on a quantitative evaluation of a group-based programme designed to promote parent infant attachment and child development. Whilst group based parenting programmes are recommended for treating and preventing conduct disorder in older children, there is, as yet, little evidence as to whether they have a positive effect on very young children and their carers’. Recent UK Government initiatives to support families and improve parenting skills in the first 2 years of children’s lives have increased the demand for the delivery and evaluation of community-based programmes. Eighty mother–child dyads were recruited from nine areas to intervention (n = 54) and control condition (n = 26). Baseline measures were collected in the children’s home when the infants were on average 3-months-old, and follow-up measures were collected 6 months post-baseline (N = 63). Mothers’ positive play behaviours were independently coded from video recordings taken in the home. Other measures included self-reported maternal confidence and mental well-being, assessed infant development and home environment. Socio-demographic data was collected once at baseline. After controlling for baseline scores, control mothers were observed to be significantly less sensitive during play with their baby at the 6 months follow-up with a significant increase in confidence. No differences were found between the groups on the other measures. This paper provides limited evidence for the effectiveness of the Incredible Years Parents and Babies group-based programme delivered in the first year of life. Further evaluation, particularly with parents at increased risk of poorer outcomes is needed to confirm and extend these results.