Abstract Substance abuse affects both the user and the family system as a whole, yet substance abuse treatment is centered on the user, leaving the family in the background. Objective: To identify the symptoms of codependency and health issues in the codependent family members of drug users who called a toll-free telephone counseling service. In total, 505 family members participated in this cross-sectional study. Drug users’ mothers and wives who had less than 8 years of education and those who were unemployed had a greater chance of high codependency. It was also determined that a high level of codependency imposed a significant burden on the physical and emotional well-being of those affected, resulting in poor health, reactivity, self-neglect and additional responsibilities. It was concluded that codependency has a negative impact on the family system and on the health of the family members of drug users.