The findings show that the children of drug-dependent parents experienced a number of harms due to their parents' drug dependency. Some children were at risk of having access to illegal drugs, and some were exposed to criminal behavior and drug dealing. They were also at risk for serious neglect and, in some cases, violence. The severity of the impact of parents' drug dependency varied according to a number of factors, including the kind of drug used, the duration of drug dependency, the presence of a partner who did not use drugs, and the involvement of extended family members in the parenting of the children. Harmful parenting behaviors were more prevalent among heroin-dependent than opium-dependent parents. Heroin dependence had a more destructive impact on both the quality and quantity of communication between parents and children. Discipline and control over family affairs were more severely damaged for heroin-addicted parents. These findings suggest that drug treatment centers in Iran should be attentive to the responsibilities of drug-dependent individuals as parents, particularly for heroin-dependent clients. Permission for this study was obtained from Iran's Welfare Organization, and it provided a list of names of substance-abusing male and female parents. Drug-dependent parents were selected through purposive sampling from participants at the Self-Referred Drug Addicts Treatment Center in Rasht. Forty-one drug dependent parents (30 fathers and 11 mothers) participated in semistructured interviews about their parenting behaviors. Eighteen of the fathers were opium-dependent, and 12 were heroin-dependent. Among the women, seven were opium-dependent, and four were heroin-dependent. 22 references