In Western Europe, works councils are a common form of indirect employee participation in management decision making. Trust is often assumed to play an important role in the nature and outcomes of labour negotiations and in management-works council consultations. So far, however, the antecedents of trust in management within works councils have not been studied. Using longitudinal data collected among the members of 75 Dutch works councils, the current study tests predictions regarding the relative influence of instrumental vs relational antecedents on the level of trust in management among works council members. An important role of instrumental predictors (eg. perceived influence of the works council on management decision making) supports a view of trust as a calculative phenomenon. On the other hand, strong effects of relational predictors would lend support to trust as a relational phenomenon. The data show that trust in management among works council members is related to relational rather than instrumental antecedents.