Involvement in relationally aggressive conduct is an important contributor to maladaptive functioning in both childhood and adulthood. Decreased emotional awareness and impairments of self-control are risk factors for relational aggressiveness, while emotional awareness can also be treated as an important prerequisite for proper self-control. The aim of the study was to examine the associations between dimensions of emotional awareness (attention to emotions and emotional clarity), self-control, and relational aggressiveness. Self-control was also examined as a mediating variable between emotional awareness and relational aggressiveness. Self-report measures of trait meta-mood, alexithymia, self-control, and relational aggressiveness were completed by 214 adolescents (129 females), aged 15–23. The confirmatory factor analysis confirmed two factors of emotional awareness: (1) inattention to emotions (reflecting low attention to emotions and externally oriented thinking) and (2) a lack of emotional clarity (reflecting difficulties in identifying emotion, difficulties in describing emotion, and low clarity of emotion). Self-control and mood repair ability inversely correlated with proactive and reactive relational aggressiveness, whereas the clarity component of the meta-mood trait only inversely predicted reactive relational aggressiveness. Structural equation modeling (SEM) showed that direct relationships between inattention to emotions and relational aggressiveness, as well as between lack of emotional clarity and relational aggressiveness were non-significant. Nevertheless, a lack of emotional clarity was indirectly and significantly associated with relational aggressiveness through decreased self-control.