The purpose of this paper is (1) to view the aims and specific objecti
ves of occupational health service systems and (2) to highlight some e
ssential concepts and methods of health systems research in the evalua
tion and development of occupational health services. None of these ta
sks will succeed if the objectives of such services are not defined, o
r if the links with the different interest groups, (employers, employe
es and state) and with the primary health care are not taken into cons
ideration.