This article first examines three areas of occupational health: the work of the International Commission on Radiological Protection (ICRP), the work on chemicals of the American Conference of Governmental Industrial Hygienists (ACGIH), and the International Labour Organization (ILO) Convention and Recommendation on Occupational Health Services. All three areas are criticized, using the notion of a "scientific strategy" which is the use of bodies of scientific knowledge and techniques in approaching occupational health. In the first two areas, it is contended that a misguided scientific strategy has been adopted which is a comment on the role of scientists in policy-making. In the third case, it is argued that the Convention and Recommendation emphasize the remedial aspects of occupational health to the detriment of the preventive side, a reflection of the undue influence of industrial medicine on occupational health. A proper approach to occupational health would make very different demands on science and would employ engineering techniques at the expense of the medical disciplines. As it is, occupational health is out of focus.