How do unionization and collective bargaining affect firm profitability? In this paper, we revisit this question using a nationally representative sample of French establishments. In addition to examining union/non-union differences in profitability, we explore the possible sources from which unions capture profits. The results indicate that unionization in France is associated with poorer financial performance in the workplace. The results also indicate that concentration-related profits do not provide an important source of union rents in France. Finally, this study provides strong support for the hypothesis of union appropriation of the returns from long-lived physical capital.