The Home Improvement Clubs are one of the most important kinds of voluntary educational and social groups in rural Taiwan. The operating effectiveness of these groups is influential to the success of home economics extension work. This study examines the group cohesiveness of Home Economics Improvement Clubs and analyzes the factors affecting group cohesiveness and the cohesiveness-performance effect. This examination aims to provide some useful recommendations to the home economics extension work;One hundred and eight club leaders and 216 club members were asked to express their thoughts about some of the group characteristics of Home Economics Improvement Clubs to which they belong, including group cohesiveness, group performance, club leadership, leadership of extension workers, degree of organizational support, degree of family support, group members' homogeneity, members' learning motivation, and members' interaction. Thirty-six extension workers were also interviewed;The findings show that the subjects gave very positive evaluations about all items measuring group cohesiveness. The results from structural equation modeling demonstrate that extension workers' leadership, group age, members' interaction, and learning motivation have significant positive effects on group cohesiveness. However, the cohesiveness-performance effect is not significant;Based on the research findings this study proposes four recommendations for home economics extension work: (1) to strengthen the vertical and horizontal linkages between related organizations; (2) to carry out more activities and programs for group member participation, (3) to enhance training programs for extension workers; (4) to enhance training programs for club leaders. The limitations of this study and some directions for future research are also discussed.