As self-esteem is likely to build on favorable social experiences, such as those derived from achievement (i.e., GPA) and social competence, emotional intelligence is likely to be pivotal in fostering social experiences conducive to self-esteem. Accordingly, emotional intelligence is likely to underlie social competence and mediate the contribution of achievement to self-esteem. This uncharted role is the focus of this study, which surveyed 405 undergraduates in Hong Kong, China. Results demonstrated the pivotal role of emotional intelligence. Essentially, emotional intelligence appeared to be a strong determinant of self-esteem and explain away the positive effect of social competence on self-esteem. The results imply the value of raising emotional intelligence in order to consolidate the basis for the young adult's self-esteem.