Parents of 211 adopted children, now young adults, were interviewed about their children's behaviour and development during childhood and adolescence. The children were placed for adoption at different ages. The quality of children's pre-placement care also varied, older-placed children generally experiencing adverse backgrounds prior to joining their adoptive parents. Depending on their quality of pre-placement care, the children were placed in one of three groups for the purposes of analysis: (a) baby adoptions, (b) older-children adoptions in which children had enjoyed satisfactory care as babies, and (c) older-children adoptions in which children had experienced adverse care as babies. The rate of adolescent problem behaviours varied between the three groups, with the older-children adoptions/adverse baby care group showing the highest rates. Two subgroups were identified. A quarter of the baby-adopted children were reported to have had problem behaviours during adolescence. In contrast, no problem behaviours were reported in 28% of the older-adopted/adverse baby care children. Some possible risk and protective factors are explored.