The current study investigates the impact of Leadership Styles (LS) and Emotional Intelligence (EI) on Project Success (PS) through underlying mediating mechanism of Job Satisfaction (JS) and trust. Total 160 responses were received from the team leaders (project managers, project leaders, project coordinators) of the NGOs sector of Pakistan. The findings of the research show that the relationship of LS and EI have significantly positive impact on the PS. Further, JS and Trust is positively and significantly influencing the PS and mediate the relationship of both LS and EI with PS. Within leadership styles, transactional leadership and Laissez Faire leadership styles have positive relationship with PS. However, the negative relationship of transformational leadership with PS is somewhat surprising as this relationship was expected to be positive.  The findings suggest that project managers in NGOs must be aware of the impact of certain leadership behaviors and level of emotional intelligence for completing the projects successfully.