Objective To use evidence from systematic reviews of environmental influences on childhood overweight to prioritise areas for development of public health interventions. Design Systematic literature reviews of intervention and longitudinal studies of environmental factors which could influence overweight via diet and/or physical activity, followed by a questionnaire-based ranking exercise for (a) the strength of the evidence for a causal association between the environmental factor and childhood overweight and (b) the likely effect size of public health actions on each factor on the prevalence of overweight in children. Environmental factors for which there was both strong evidence of causality and a larger effect size were selected for detailed modelling of the likely impact of public health interventions in children in Scotland. Setting Children up to 8 years in Scotland. Participants Academics and policy makers with experience of reviewing evidence of public health interventions on obesity. Main Outcome Measure Ranking of environmental factors to identify those which should be prioritised for future public health interventions. Results Of the twenty-four environmental factors initially identified at stakeholder workshops, no studies were found for three factors influencing physical activity and one factor affecting diet. For the remaining twenty factors a median of six (range 1–28) studies were identified and summarised in tabular form. Fourteen academics and policy makers were given the tables to complete the rating exercise, which took approximately 1 h. The strength of the evidence and the likely effect size of actions were rated on a scale of 0 (low) to 5 (high). Eight of the environmental factors obtained mean ratings >3 for both strength of evidence and likely effect size: six were factors related to diet (high energy-dense snacks, sugar-sweetened soft drinks, infant feeding, availability of high fat, sugar and salt foods and portion size of manufactured foods and of restaurant and cafeteria items) and two were related to physical activity (physical education in schools and sedentary leisure activity). The ratings were lowest for access to local amenities, safe routes to schools and provision of healthy foods in schools. Conclusion The ranking exercise provided a structured approach for obtaining a consensus view on priorities for public health action using tables of evidence from a systematic review. Use of this approach with a larger number academics and policy makers from different sectors would be useful to assess whether the area of expertise and sector (academia vs policy) influences the rating of the evidence.