Evaluation of clinical ethical case consultations has been discussed as an important research task in recent decades. A rigid framework of evaluation is essential to improve quality of consultations and, thus, quality of patient care. Different approaches to evaluate those services appropriately and to determine adequate empirical endpoints have been proposed. A key challenge is to provide an answer to the question as to which empirical endpoints—and for what reasons—should be considered when evaluating the quality of a service. In this paper, we argue for an approach that adopts the role of ethics consultants as its point of departure. In a first step, we describe empirical and ethical characteristics of evaluating clinical ethical case. We show that the mode of action and the explicit normative character of the interventions constitute two characteristics which pose challenges to the selection of appropriate quality criteria and require special attention. In a second step, we outline the way in which an analysis of the role of ethics consultants in the context of a clinical ethical case consultation services can account for the existing challenges by linking empirically measurable endpoints with normative theory. Finally, we discuss practical implications of our model for evaluation research.