BACKGROUND: The Public Health Responsibility Deal (RD) in England was launched in 2011 as a public-private partnership which aims to 'tap into the potential for businesses and other influential organisations to make a significant contribution to improving public health by helping us to create this environment'. It has come under criticism from public health advocates and others, who have suggested that it will be ineffective or perhaps even harmful. Like many public health policies, there have also been demands to know whether it 'works'. METHODS: We conducted a scoping review and used this, supplemented with interviews with stakeholders, to develop a detailed logic model of the RD (presented here) to help understand its likely outcomes and the pathways by which these may be achieved as a basis for planning an evaluation. CONCLUSIONS: Evaluations of complex interventions require not just assessment of effects (including outcomes), but also a clear conceptualization of the intervention and its processes. The way the RD and the pledges made by participant organizations has been presented makes it difficult at this stage to evaluate whether the RD 'works' in terms of improving health. Instead, any evaluation needs to put together a jigsaw of evidence about processes, mechanisms and potential future health and non-health impacts, in part using the current scientific evidence. This task is ongoing.