Although people have intentions to change their behavior, many do not take any action, and this discrepancy is called the intention-behavior gap. Studies estimate the gap is as high as 50%, a figure of some significance in health behavior change. This paper explores the intention-behavior gap in the context of social prescribing in the UK. It looks at the current problems of measurement and evaluation within social prescribing and the potential impact of the intention-behavior gap. The paper also considers the current research addressing the gap and proposes an alternative solution based on a positive psychology framework and positive psychology interventions. Research for these proposals is drawn from the field of motivation science, and the positive psychology models and concepts of self-determination theory, mindfulness, and positive emotions.