The peer relationships of young children with mild developmental (cognitive) delays recruited at 4--6 years of age were examined in a longitudinal study across a 2-year period. Results revealed only modest increases in children's peer interactions, a high degree of intraindividual stability, and the existence of a poorly organized and conflict-prone pattern of peer interactions. Child cognitive and language levels as well as family stress and support were associated with children's peer interactions. A subgroup was identified of initially low interactors who were at especially high risk for future peer interaction problems. These findings further underscore the importance of designing and implementing early intervention programs in the area of peer relationships for children with mild developmental delays.