Attachment status of children exposed in utero to cocaine, opiates, and other substances was examined at 18 months (n=860) and 36 months (n=732) corrected age. Children exposed to cocaine and opiates had slightly lower rates of attachment security (but not disorganization), and their insecurity was skewed toward ambivalent, rather than avoidant, strategies. Continued postnatal alcohol use was associated with higher rates of insecurity and disorganization at 18, but not 36, months of age. Stability of attachment across the 18-month period was barely above chance expectation. Attachment status at 18 months was associated with child temperament and caregiverchild interaction; at 36 months, attachment was associated with child temperament, child behavior problems, and caregivers' parenting self-esteem.