The need to evaluate the performance of clinical ethics services is widely acknowledged although work in this area is more developed in the United States. In the USA many studies that assess clinical ethics services have utilized empirical methods and assessment criteria. The value of these approaches is thought to rest on their ability to measure the value of services in a demonstrable fashion. However, empirical measures tend to lack ethical content, making their contribution to developments in ethical governance unclear. The steady increase of clinical ethics committees in the UK must be accompanied by efforts to evaluate their performance. As part of this evaluative work it is important to examine how the practice of clinical ethics committees can be informed by empirical measures.