Facial expressions play a crucial role in the nonverbal communication of everyday life. Thus, the understanding of how they modulate our behavior is crucial for elucidating social interactions. However, empirical evidence is highly contradictory, likely because i) different types of emotions have been used interchangeably; ii) the effect of stimuli valence has often not been disentangled from that of the arousal; iii) the task-relevance of emotional stimuli has rarely been considered. In the present research, we assessed the effect of happy, fearful, and angry faces on the motor response, considering both their arousal and relevance for the on-going task. We showed that i) stimuli valence affects motor behavior only when emotions are task-relevant; ii) angry faces interfered more than other expressions, but qualitatively had the same effect of fearful faces with respect to happy faces. We discuss the relevance of these findings to the decision-making process and social-emotional functioning. **Key Words**: motor control, emotion, facial expressions, decision making, Go/No-go task