OBJECTIVES: Survival among children diagnosed with acute lymphoblastic leukaemia (ALL) has increased considerably. However, morbidity in survivors constitutes a potential increasing burden not limited to secondary health care. Our objectives were to compare health care utilisation, including both primary and secondary health care, between childhood ALL survivors and matched references up to 15 years after curative treatment. Moreover, to increase knowledge on survivors' health service seeking behaviour as time from treatment elapsed. DESIGN AND SETTING: A Danish population-based matched cohort study linking multiple nationwide registries. PARTICIPANTS: 675 cases, diagnosed with childhood (1.0-17.9 years) ALL between 1994 and 2015, and 6750 matched references sampled randomly from the source population (matched on age, gender and geographical region). PRIMARY OUTCOME MEASURES: Repeated consultations in general practice and hospital (outpatient and inpatient) estimated as yearly rates from 2.5 years after diagnosis and onwards. We compared cases and references with yearly incidence rate ratios (IRRs) from negative binomial regression models. RESULTS: Survivors of childhood ALL had a mean number of yearly daytime contacts in general practice of 4.75 (95% CI 4.41 to 5.11) the first year, corresponding to an IRR of 1.85 (95% CI 1.71 to 2.00); decreasing to 1.16 (1.01 to 1.34) after 15 years, and without significant impact of gender (p=0.894) or age (p=0.399). For hospital contacts, ALL survivors had a mean number of yearly contacts of 14.21 (13.38-15.08) the first year, corresponding to an IRR of 31.50 (28.29-35.07); decreasing to 2.42 (1.59-3.68) after 15 years. No differences were found across calendar time. CONCLUSIONS: ALL survivors used significantly more health care services across sectors than the reference population. Decreasing use over 15 years illustrated the dynamics of health care needs; this knowledge may inform the future organisation of integrated follow-up programmes. TRIAL REGISTRATION NUMBER: NCT03985826.