Objective There are three main objectives of this study. First, this study is to examine the influence of union effectiveness and perceived union support on union relationship capital to achieve positive mental health in the workplace. Next, this study is to investigate the interdependency of the dimensions of union relationship capital: communication, trust and commitment between the union leader and union members in improving and strengthening the relationship within the union. Lastly, this study is to investigate the role of relationship capital as the mediator between union effectiveness, perceived union support and mental health.

Methodology/Technique A total of 600 questionnaires completed by trade union leaders and members in manufacturing sector based in Peninsular Malaysia were analysed using SEM (AMOS) and SPSS. The relationship between union effectiveness, perceived union support, union relationship capital and mental health were analysed using SEM. But the interaction between communication, trust and commitment were analysed using SPSS.

Findings The results demonstrated that union effectiveness and perceived union support are determinants for union relationship capital. The finding showed that communication, trust and commitment are interdependent. Furthermore, the finding also shows a significant relationship between union relationship capital and mental health.

Novelty : It is said that good communication, trust and commitment within the trade union can increase cohesiveness and strengthen the trade union. A strong union can lead to positive mental health in the workplace.

Type of Paper: Empirical

Keywords: Union Leader- Member Relationship Capital, Mental Health, Malaysia.