To be successfully and sustainably adopted, policy-makers, service managers and practitioners want public programmes to be affordable and cost-effective, as well as effective. While the realist evaluation question is often summarised as what works for whom, under what circumstances, we believe the approach can be as salient to answering questions about resource use, costs and cost-effectiveness – the traditional domain of economic evaluation methods. This paper first describes the key similarities and differences between economic evaluation and realist evaluation. It summarises what health economists see as the challenges of evaluating complex interventions, and their suggested solutions. We then use examples of programme theory from a recent realist review of shared care for chronic conditions to illustrate two ways in which realist evaluations might better capture the resource requirements and resource consequences of programmes, and thereby produce explanations of how they are linked to outcomes (i.e. explanations of cost-effectiveness).