A conflict of interests occurs when a doctor is unduly influenced by a secondary interest (i.e., a personal incentive) in his acts concerning one of the primary interests to which he is professionally committed (the welfare of patients, the progress of science or the education of students or residents). One specific variety of conflicts of interests has monopolized the attention of the scientific and lay press: the financial conflicts of interests arising from the relationships between doctors and drug companies. A large literature has described the many, sometimes subtle, ways by which a psychiatrist can be influenced in his prescribing habits or research activities by his relationships with the industry. Some empirical evidence is now available in this area. On the other hand, it has been pointed out that the current debate on this issue is sometimes "affectively charged", or fails to take into account that the interests of patients, families and mental health professionals and those of the industry may be often convergent. Other types of conflicts of interests are beginning now to be discussed. There is evidence that the allegiance of a researcher to a given school of thought may influence the results of studies comparing different psychotherapeutic techniques, thus colliding with the primary interest represented by the progress of science. Political commitment is also emerging as a source of conflicts of interests. Financial and non-financial conflicts of interests are widespread in psychiatric practice and research. They cannot be eradicated, but must be managed more effectively than is currently the case.