The purpose of this research project was to evaluate a preventative parent-training programme delivered as part of the community wide Flying Start (FS) initiative. Flying Start was introduced in 2007 across Wales with the aim of increase service provision for families in Wales living in areas earmarked by the Welsh Government (Welsh Government) as experiencing high levels of deprivation. The Welsh Government provided Bangor University with 114k to independently evaluate the delivery ofIncredible Years Toddler parenting programme (IYTPP) in Flying Start community settings, alongside the other three components of Flying Start. This funding, along with three years of PhD funding for the thesis author provided by the Coleg Cymraeg Cenedlaethol provided the opportunity to conduct three studies. The first study explored the baseline characteristics of the small sample that were recruited for the RCT trial in terms of level of risk and need of intervention. Risk factors for poor child outcomes were identified and comparisons drawn with a previously recruited sample of disadvantaged families that took part in an RCT of a parenting intervention within Sure Start services (Hutchings et al. 2007). The second study evaluated the short-term effectiveness of the IYTPP using a rigorous RCT design, comparing families allocated to receive the IYTPP intervention with control families. The third study explored the longer-term effects of intervention for families who had provided data across a twelve month period, and explored whether the intervention had different effects for the families who were experiencing elevated levels of the risk-factors identified in study one. The study concluded that to effectively allocate resources to families with the greatest needs, additional targeting measures identifying individual level of risk should be utilised. Delivery of the intervention saw modest short-term improvements in parental mental well-being for intervention families. Long-term findings support the work of others, demonstrating sustained improvements, with families experiencing elevated levels of risk seeing comparable, and often greater improvements when compared with families with a lower level of risk.