This article presents the findings of a qualitative study of parents' perceptions of a video-modelling assisted group-based parent training programme, the Parents Plus Children's Programme (PPCP). PPCP was developed in Ireland and is culturally sensitive to the Irish context. PPCP aims to reduce emotional and behavioural difficulties in children aged 6-11 years. Twenty-one caregivers of children attending a child and adolescent mental health service in Dublin with significant behavioural problems were interviewed five months following completion of PPCP. Thematic analysis was used to explore caregivers' perceptions of changes in their children, benefits of participation and effective programme strategies, with a view to identifying cognitive factors mediating outcome. Improvements observed included children being calmer, being better able to communicate feelings and needs, and having better emotional regulation. "Tuning in" to children, engaging in play, explaining rules, communicating calmly and planned sanctions were identified as effective programme strategies. Group support emerged as the main benefit of participation. Perceived parental control, ability to reframe children's misbehaviour, consistency with discipline and hopefulness differentiated participants who observed improvements and those who did not. The findings were interpreted within a social-cognitive theoretical framework with reference to self-efficacy beliefs. Implications for clinical practice are also discussed.