This thesis has considered findings from evaluations of parenting programmes which have traditionally used outcome measures of negative affect and behaviour to measure change. Drawing on the considerable body of research on parenting programmes and their theoretical basis Paper 1 advances a line of argument about the potential for incorporating measures developed from research in the area of positive psychology. Extending outcomes of interest to incorporate measures of positive affect, attitudes and behaviour has the potential to contribute to our understanding of the mechanisms of change. No studies of parenting programmes using positive outcome measures were identified. Paper 1 concludes that future research of parenting programmes could begin to investigate the role of positive emotions as mechanisms of change. Paper 2 aimed to examine session-by-session changes in gratitude, positive and negative affect, satisfaction, authenticity, self-efficacy, defeat and entrapment in parents attending a Triple P Positive Parenting program. This study found that entrapment had a significant concurrent relationship with gratitude, negative and positive affect, authenticity, and satisfaction with life. Entrapment was also found to be a significant predictor of session by session change with lower levels of entrapment predicting increases in gratitude, negative and positive affect, and satisfaction. The study concludes that reductions in entrapment are a significant predictor of increases in positive affect and attitudes in carers attending a parenting programme. Paper 3 is a critical reflection and considers both Paper 1 and Paper 2. Within this paper the approaches used, the challenges encountered, and future research are considered.