This study examined the formation and quality of attachment of 65 postinstitutionalized (PI) toddlers with their parents at 1-3 and 7-9 months postadoption compared to 52 nonadopted (NA) children. The formation of attachment relationships of PI children with adoptive parents occurred relatively quickly. Children exposed to greater preadoption adversity took longer to form an attachment to their adoptive parents, although by 7-9 months postadoption, nearly all (90%) of the children achieved the highest level on an attachment formation rating scale. PI children did not differ from NA children in attachment security, based either on the Attachment Q-Sort or Strange Situation categorical scoring. However, the PI children were more likely to be disorganized in their attachment patterns. Preadoption adversity was related to lower Q-sort security scores especially at the initial assessment 1-3 months postadoption. The results indicated that attachment formation and attachment quality in PI children are differentiable constructs with different precursors.