This study examines the relationships between individualized consideration (IC), interpersonal justice (IJ), psychological uncertainty (PU) and job performance (JP) among non-managerial employees in Bosnia and Herzegovina’s public and private sectors. It investigates whether IC positively influences JP and IJ, with IJ mediating the IC-JP relationship and whether PU negatively affects JP. Data from 449 employees were analyzed using partial least squares structural equation modeling (PLS-SEM) and multi-group analysis (MGA). Results show that IC directly positively affects JP in the public sector but not in the private sector, with a statistically significant difference. IJ positively influences JP in private but not public sector, also with a statistically significant difference. PU negatively affects JP in public but not private sector, though sectoral differences are not significant. These findings underscore the contextual nature of leadership and justice perceptions in shaping JP, emphasizing the need for sector-specific strategies.