In an increasingly volatile labor market, organizations need to find ways to improve employees’ trust in order to retain them. This study uses data from 212 employees from the Tanzania Revenue Authority (TRA) in Tanzania to examine the effect of organizational justice and level of trust on job satisfaction across different groups of employees by gender and tenure. The study proposed that the level of trust would mediate the influence of organizational justice on job satisfaction levels of all employees and within employee sub-groups categorized by gender and tenure. The study then confirms the hypotheses by using structural equation modeling (SEM). The findings highlight the importance of trust in the organization but within groups, the effect is more profound in female than male employees, and more on employees with longer work tenure. Implications of the findings are discussed.