Occupational health services face important changes as a result of changes in work environment, changing health and safety concepts, and legislation. To ensure good quality at a good price, it is important to control the processes in occupational health services. The concept of "prevention pathways" is presented for the management of occupational health services. The model is based on the critical pathway concept. The approach is illustrated by means of a case study performed in a Belgian occupational health service. A prevention pathway for the evaluation of chemical risks at the workplace was constructed. The prevention pathway methodology revealed inefficiencies and quality problems in the current practice of chemical risk assessment and biomonitoring. The case shows how prevention pathways can be used to pilot the members of a multidisciplinary team by focusing on a specific occupational risk.