Differences in attraction to same- and other-sex peers as a function of sex, age, individual characteristics (i.e., aggression), and context were examined in a longitudinal study of early adolescent boys and girls (N = 217) that covered the transition from elementary school (Time 1) to middle school (Times 2 and 3). Consistent with T. Moffitt's (1993) concept of the "maturity gap," attraction to aggressive peers, especially attraction to aggressive boys among girls, increased with age and upon entry to middle school, as did attraction to peers who stood out in the peer group in easily observable ways. Attraction to peers who presented features associated with good classroom-based behavior decreased. These patterns are discussed in terms of the developmental needs served by associating with particular peers.