Sixty-six infants born to amphetamine-addicted mothers were followed during their first year of life. The children were divided into three groups, according to whether or not the mother stopped her abuse in early pregnancy (Group I) or continued (Group II) and whether or not the latter children were placed in foster homes immediately after birth (Group III). All but 2 of 16 mothers in Group I stayed off drugs and mostly met non-addicted friends. In Group II, on the contrary, all but 2 of 36 mothers continued their abuse one year after delivery. At the age of one year, all but one child in Group I were in their mothers' custody and all children in Group III had remained in foster care. In Group II one-third of the children lived in foster homes after revocation of the maternal custody. Several infants in Group II had experienced multiple transfers between the biological home and different foster homes. There were indicators that maternal amphetamine abuse causes temporary drowsiness in the infants during the first months after birth. However, all children at the age of 12 months, regardless of group, had a somatic and psychomotor development in accordance with the normal Swedish standard. In all groups there was an increased rate of medical care mainly because of infections. Some infants in Group II compared to none in Groups I and III were hospitalized because of failure to thrive or suspected physical abuse. Symptoms indicating emotional disturbance were more common in infants of Group II than in infants of Groups I and III.