Mimicry is functional for empathy and bonding purposes. Studies on the consequences of mimicry at a behavioral level demonstrated that mimicry increases prosocial behavior. However, these previous studies focused on the mimickee. In the present paper, we investigated whether mimickers also become more helpful due to mimicry. In two studies, we have demonstrated that participants, who mimicked expressions of a person shown on a video, donated more money to a charity than participants who did not mimic. Moreover, the processes by which mimicry and prosocial behavior are related largely remain empirically unexamined in existing literature. The results of Study 2 confirmed our hypothesis that affective empathy mediates the relationship between mimicry and prosocial behavior. This suggests that mimicry created an affective empathic mindset, which activated prosocial behaviors directed toward others.