Objectives: To review the effectiveness of social marketing interventions designed to improve diet, increase physical activity, and tackle substance misuse. Study design and methods: This article describes three reviews of systematic reviews and primary studies that evaluate social marketing effectiveness. All three reviews used pre-defined search and inclusion criteria and defined social marketing interventions as those which adopted six key social marketing principles. Results: The reviews provide evidence that social marketing interventions can be effective in improving diet, increasing exercise, and tackling the misuse of substances like alcohol, tobacco, and illicit drugs. There is evidence that social marketing interventions can work with a range of target groups, in different settings, and can work upstream as well as with individuals. Conclusions: Social marketing provides a very promising framework for improving health both at the individual level and at wider environmental and policy-levels. Problems with research design, lack of conceptual understanding or implementation are valid research concerns.