This study investigates the effectiveness of employee participation in achieving product quality improvement in union versus nonunion settings and in programs unilaterally administered by management versus programs with joint union-management administration. An analysis of data from two surveys of manufacturing firm managers suggests that among unionized firms, those with jointly administered programs achieved significantly greater improvements in product quality than did those with more traditional, adversarial collective bargaining relationships (that is, with no participation programs), but those with programs administered solely by management fared no better than those with no programs. The gains associated with jointly administered programs in unionized firms were at least equal to the gains associated with participation programs in nonunion firms.