The current process towards formalization within evaluation research, in particular the use of pre-set standards and the focus on predefined outcomes, implies a shift of ownership from the people who are actually involved in real clinical ethics support services in a specific context to external stakeholders who increasingly gain a say in what ‘good CESS’ should look like. The question is whether this does justice to the insights and needs of those who are directly involved in actual CESS practices, be it as receivers or providers. We maintain that those actually involved in concrete CESS practices should also be involved in its evaluation, not only as respondents, but also in setting the agenda of the evaluation process and in articulating the criteria by which CESS is evaluated. Therefore, we propose a participatory approach to CESS evaluation. It focuses on the concrete contexts in which CESS takes place, reflective and dialogical learning processes, and how to be democratic and inclusive. In particular, this approach to CESS evaluation is akin to realist evaluation, dialogical evaluation, and responsive evaluation. An example of a participatory approach to evaluating CESS is presented and some critical issues concerning this approach are discussed.