Background Despite expansive knowledge on the detrimental effects of growing up with parents with alcohol use disorders (AUDs), little is known about the prognosis of alcohol treatment among parents with childcare responsibility. Aims This observational cohort study aimed to examine the prognosis of patients with and without childcare responsibility, in a conventional out-patient alcohol treatment clinic. Method A consecutive AUD sample (N = 2201), based on ICD-10 Diagnostic Criteria for Research, was assessed with the European Addiction Severity Index during the clinical routine, at treatment entry and conclusion. Data on addiction severity, treatment course and drinking outcomes were derived, and adjusted odds ratios (AORs) were calculated with logistic-regression models. Drinking outcomes were compared in an intention-to-treat analysis, including all patients in a logistic regression with inverse probability weighting. Results Patients with childcare responsibility (aged <18 years) had a less severe addiction profile and lower drop-out rate compared with patients without children or with children living out-of-home. They were also more likely to improve on all drinking-related outcomes, including abstinence (AOR 2.68, 95% CI 1.82-3.95), number of drinking days (AOR 2.45, 95% CI 1.50-4.03) and excessive drinking days (AOR 4.66, 95% CI 2.36-9.17); and those with children living out-of-home had better outcomes on abstinence (AOR 1.59, 95% CI 1.08-2.34) than patients without children. Conclusions Childcare responsibility among out-patients was associated with better treatment course and outcomes than those without or not living with their children. This knowledge can help guide clinical practice, effectuate interventions and inform social authorities.