The current study examined relational aggression in kindergarten children and how it relates to aspects of their friendships over a 2-month period. Participants were 74 boys and girls (ages 5 and 6). Teacher report and peer nominations assessed relational and physical aggression. Children also rated each child in their class on liking and identified their friends. Hierarchical multiple regression analyses showed that peer nominations of relational aggression were negatively related to Time 1 liking, Time 1 number of mutual friends, and friendship stability even when teacher ratings of physical aggression were controlled. Physical aggression was also significantly related to these variables. Relational aggression (but not physical aggression) significantly predicted declines in the number of mutual friendships and liking two months later.