The present study compared 15 mothers on methadone maintenance (MM) and their 15 preschool children to 15 non-drug-addicted mothers (NDA) and their 15 preschool children on mothers' personalities and parenting attitudes, the mother-child interaction, and on children's intelligence and developmental levels. Findings showed that in comparison to the control group, MM mothers performed less adaptively on measures of personality and parenting behavior. There were no differences between the two groups of mothers on their parenting attitudes. Children of MM mothers performed more poorly than children of NDA mothers on measures of intelligence, development, and socially adaptive behavior.