Although there is a vast amount of research on leadership and improvement-oriented voice behavior, the amount of cross-lagged research on leadership that also incorporates more challenging forms of voice is sparse. This article reports on a two-wave study of white-collar workers in a Norwegian medical technology company, investigating the relationship among employees’ perceived transformational leadership behaviors, job autonomy, and promotive and prohibitive voice. Testing our results cross-lagged, we demonstrate that perceived transformational leadership is significantly related to prohibitive voice over time, whereas this effect worked in the opposite direction for promotive voice. We also explore the boundary conditions of transformational leadership, demonstrating that perceived job autonomy strengthens the effect of transformational leadership on prohibitive voice. Implications for theory and research are discussed. [ABSTRACT FROM AUTHOR]