End-users of health services can and should play a key role in health services evaluation. This chapter describes how people evaluating health services can use co-production to partner with patients, caregivers, and community members in their evaluation. Guidance will be provided to support evaluators to decide what to evaluate, when and how to measure it, and importantly what the data means and what health services should do with it to drive improvement. The “principles of co-production” are explained, and case examples are used to demonstrate how evaluators can move from a mindset of consultation, towards genuine “co-evaluation” where decisions are made together with patients, caregivers, and community members at every stage of the evaluation.