The literature on employee voice has predominantly focused on its organizational implications and antecedents, yet paid less attention to its consequences for employees who enact this behavior. This paper uncovers how, why, and when engaging in voice behavior may generate beneficial or undesirable outcomes for employees. Integrating the dual nature of voice (i.e., upward influence and contradiction against the status quo) with conservation of resources theory, we theorize how voice behavior unfolds as a double-edged sword for employees who speak up. On one hand, voice behavior increases employees’ perceived influence at work, thereby heightening their work engagement and well-being; on the other hand, voice behavior triggers employees’ anxiety about upsetting the leader, thereby leading to detrimental outcomes. We further propose regulatory foci as boundary conditions for the personal consequences of voice behavior, such that the relationship between voice and perceived influence is more pronounced among promotion-focused employees whereas the relationship between voice and anxiety about upsetting the leader is more pronounced among prevention-focused employees. Findings of two field studies using experience sampling methodology at the daily, within-individual level substantiate voice behavior as a mixed blessing for voicing employees, and hint at the personal benefits of expressing voice overall outweighing its costs. Implications for theory and practice are discussed.