This article investigates the factors that explicate the implementation of European social partner ‘soft’ framework agreements. The implementation of two such agreements, the Telework and Work-Related Stress Agreements, in four countries and two sectors is investigated. Seven hypotheses, primarily derived from the study of generic European ‘soft’ law, about the factors that explain the implementation of European social partner ‘soft’ law are tested. The article concludes that European social partner ‘soft’ law is distinctive from generic European ‘soft’ law in that its successful implementation is contingent upon the extent the industrial relations system in which it is implemented is centralized and co-ordinated.