The aim of the present study was to determine whether the self‐enhancement effect of voice attractiveness evaluation is due to general self‐positivity bias and/or the familiarity effect. The participants were asked to rate the attractiveness of their own voice, a friend’s voice and strangers’ voices. In addition, a self‐reference valence (SR‐valence) task was adopted in the experiment. Significant self‐enhancement effects in voice attractiveness ratings were demonstrated, regardless of whether the participants recognized their self‐voice or not. However, the friend‐enhancement effect was found in only those participants who successfully recognized their friend’s voice. Moreover, a significant correlation was found between self‐positivity bias in the SR‐valence task and the self‐enhancement effect (but not the friend‐enhancement effect). Our findings suggest that both the familiarity effect and self‐positivity bias account for the vocal self‐enhancement effect, and the influence of self‐positivity bias could be implicit. The present study thus provides empirical evidence to clarify the potential explanations for the self‐enhancement of voice attractiveness assessment.