Ethics committees in Britain were set up to consider clinical research. Increasingly, however, they are receiving applications for health services research which often involves several or many centres. The performance of 23 ethics committees was examined through a case-study of an application for a multi-centre non-experimental study of prostatectomy. Although all the committees approved the study, long delays occurred (mean 11.5 weeks, range 3-32 weeks), particularly in teaching districts which dealt with large numbers of applications. The composition of the committee and the frequency with which it met were not associated with the time taken to reach a decision. Some delays might be reduced by improving the design of the application forms and ensuring that at least one member of the committee has an understanding of health services research methods. Although such measures might improve the performance of committees, applicants are likely to remain in a logistic trap between funding bodies, clinicians, and ethics committees. In addition, until committees temper their concern for individualistic medical ethics with a collective ethic of the common good, health services research may continue to experience delays and difficulties.