Background: This article provides baseline measurement of health outcomes for parent and child dyads among people receiving interventions for opiate use. Method: A cohort study was implemented among 171 participants with 235 children in three urban sites in Ireland in 2010/11. Adult and child outcomes were measured using the Short Form 12, the Becks Depression and Anxiety Inventories, the Strength and Difficulties Questionnaire and the Kidscreen 27. Results: Over 60% (95% CI 52.5%-68.8%) of adult participants grew up in a household with at least one person who used substances. The main substance used was alcohol (80.7%; 95% CI 71.9%-89.5%) followed by heroin (11.4%; 95% CI 4.2%-18.6%). A correlation was found between increasing adult anxiety and growing up in a home with a person using substances (r = 0.169, p = 0.040). Children of current parents had more difficulties with emotional and conduct problems, as compared to international norms (t = 5.85, p < 0.01; t = 3.39, p < 0.01). Correlations existed between current parental depression and anxiety and child conduct disorder (r = 0.344, p = 0.008; r = 0.374, p = 0.004). Conclusions: Parents who use drugs are part of the so-called 'sandwich generation'. Monitoring and evaluation of interventions that address outcomes across generations of parental and child dyads are lacking.