The current study examined to what extent early adolescents’ implicit and explicit evaluations of a classmate predict (a) their own aggressive behavior toward that classmate and (b) their classmate’s aggressive behavior toward them. Implicit and explicit peer evaluations were assessed among 148 early adolescents (78 boys and 70 girls; Mage = 11.1 years) with an approach–avoidance task and a likeability rating. Adolescents’ aggression was measured by the number of grams of hot sauce administered to the peer in a “taste test.” The analyses with the actor–partner interdependence model showed that girls’ implicit attitude predicted aggression toward their partner and that boys’ implicit attitude predicted their partner’s aggression toward them. Explicit attitudes did not predict “hot sauce” aggression. The current study demonstrates that implicit evaluation of a peer can in fact be even more impactful than explicit evaluation in social interactions among peers.