This paper reports the results of an experimental study examining the joint effect of two group characteristics, responsibility and cohesiveness, on escalation of commitment in an ongoing unsuccessful project. Two levels (high/low) of group responsibility and group cohesiveness were manipulated to examine their effects on group escalation decisions. Forty-eight 3-member decision groups were formed and randomly assigned to four treatment cells with 12 groups in each cell. The results of a 2×2 ANOVA reveal a significant main effect of responsibility on escalation of commitment, as well as a significant interaction of responsibility and cohesiveness. Specifically, groups with both high responsibility and high cohesiveness committed the largest amount of resources to an ongoing unsuccessful project. These results provide support for the proposition that group responsibility and cohesiveness exert significant joint effects on group escalation of commitment in an ongoing unsuccessful project. The findings suggest that periodic changes of group membership to shift responsibility and cohesiveness may generate new attitudes and views to reduce group escalation of commitment.