This article describes the prophylactic programmes for health surveillance which exist in the occupational environment in Denmark. Compared with other industrialised countries, Denmark has only few established surveillance programmes. Nevertheless, these investigations exist, particularly in the form of non-specific general clinical health investigations at local workplaces, in certain branch agreements and in certain types of work. In addition, the article provides a review of the literature concerning health and health-economic effects of supervision of health. It is concluded that with the existing knowledge, pre-employment examinations and periodic health examinations as routine examinations without and clearly defined object must be regarded as having limited prophylactic value and that examinations of this nature can scarcely give the worker any health benefit or give the employer any economic profit. On the other hand, programmes of this nature may give the employees a false sense of security and contribute towards interpreting of justifiable levels of exposure, on an incorrect basis. Biological monitoring and occupational medical screening include, as a rule, more well directed programmes which will probably be employed to a greater extent in the coming years. Finally, a set of American directives for criteria of utilization, particularly for screening in occupational medicine are discussed. It is maintained here, among other things, the necessity of an integrated analysis of biological monitoring, screening and control of exposure so that health surveillance can be of benefit for all the employees at a workplace and not only the individual worker.