Despite the growing attention given to the connection between transformational leadership (TL) and job performance (JP), the precise mechanisms driving this association remain inadequately understood. This research delves into diverse causal factors that elucidate the TL–JP relationship. Drawing upon both TL theory and self-determination theory, the study explores the mediating role of employee participation in developing performance measures (PM participation) and public service motivation in the TL–JP relationship. The survey encompassed 208 pairs of employees and their direct managers operating in 208 different public organizations in Vietnam. Employing partial least square regression, the study validates that PM participation and public service motivation partly mediate the TL–JP relationship. The findings furnish valuable insights for managers seeking to enhance the performance of public employees in Vietnam and within emerging economies characterized by comparable structures. Points for Practitioners This study advocates for public sector leaders to adopt a transformational leadership approach. It emphasizes the importance of encouraging employee participation in the design, implementation and improvement of performance measures. Such engagement is anticipated to boost public service motivation, subsequently contributing to increased work efficiency among employees.