Models for strategic priority setting in public health and health services research typically lack coherence or omit key considerations. We propose a new model, the Seven 'I's, with seven components: innovation, identification, inequalities, incorporation, importance, influences, and interventions. It tests the 'relevance' of research, while 'excellence' will be evaluated using existing criteria for peer review. It should be used to set research priorities primarily on the basis of expected health benefits, with adjustments for other non-health benefits as necessary. We discuss each component and compare our approach to other models. We argue that our model helps ensure resource allocation is transparent and accountable, and encourages the link to population health gains. It is flexible, and is applicable to both commissioned and investigator-driven research. It may be applied to assess existing proposals, or to generate research ideas.