Workers sometimes violate, more or less deliberately, Quality Management System ( QMS) procedures and rules, and two of the most essential causes of such violations are the attitude and motivation of the workers. The effectiveness of a QMS may therefore benefit from management tools aimed at promoting desired behaviour. The result could then be a behaviour-oriented frame for the QMS. The concept of individual accountability, a pivotal concept in performance management models, may serve to develop such a frame. In this study, the relationship between individual accountability factors and the effectiveness of a QMS is investigated. Individual accountability is conceived of as the interplay among three factors: system clarity, social support and personalized responsibility. Data were obtained by conducting a survey and by interviewing employees of a large gas company. We found positive relationships between all three accountability factors and belief in the QMS as well as use of the QMS. Personalized responsibility and social support appeared to strengthen the relationship between system clarity and belief in the QMS, whereas the same factors appeared to weaken the relationship between system clarity and use of the QMS. Apart from being motivators in themselves, the three accountability factors thus seem to form a system of interrelated factors.