Bioethical and bio-political questions are increasingly tackled by committees, councils, and other advisory boards that work on different and often interrelated levels. Research ethics committees work on an institutional or clinical level; local advisory boards deal with biomedical topics on the level of particular political regions; national and international political advisory boards try to answer questions about morally problematic political decisions in medical research and practice. In accordance with the increasing number and importance of committees, the quality of their work and their functional status are being subjected to more and more scrutiny. Besides overall criticism regarding the quality of their work, particular committees giving political advice are often suspected of being incompatible with democratic values, such as respect for affected parties, representation of diverse values and transparency in the decision-making processes. Based on the example of the German National Ethics Council, whose inauguration caused a still ongoing debate on the aims and scopes of committees in general, this paper discusses: (1) the requirements of modern democratic societies in dealing with complex scientific-technical problems; (2) the composition and organisation of committees working as political advisory boards; and (3) the appointment procedures and roles of laymen and experts, and here in particular of ethicists, who may legitimately be taken on by a committee. I will argue that bioethics committees do not necessarily endanger democratic values, but can considerably improve their realisation in democratic decision-making procedures--if, and only if, they do not act as substitutes for parliamentarian processes, but help prepare parliamentarian processes to be organised as rationally as possible.