Although it is hypothesized that children with different insecure attachment patterns may experience a variety of peer difficulties, the question has been investigated almost exclusively for externalizing and internalizing behaviors with peers. The purpose of this study was to investigate how each of the insecure attachment patterns is related to other features of peer relationships using data from the NICHD SECC (N = 1,140 families). Secure children were rated by mothers and teachers as less excluded by peers than avoidant and disorganized children, although the latter was only significant for boys. No behaviors were uniquely associated with ambivalent children. Avoidant children were rated high by mothers and teachers on asocial behavior, and lowest by teachers on relational aggression. Disorganized children were rated low by mothers on prosocial behavior and high on peer victimization as reported by mothers and teachers. Teachers rated disorganized children as showing higher levels of relational aggression than securely- and ambivalently-attached children. The pattern of findings revealed mixed evidence for the specificity hypothesis.