AIMS: Undertreatment with evidence-based pharmacotherapy for heart failure (HF) is an important problem, and it has been suggested that specialized HF clinics (HFCs) can improve treatment initiation and correct dosing. The objective of this study was to examine long-term adherence to and dosages of evidence-based pharmacotherapy during and after participation in specialized HFCs. METHODS AND RESULTS: Initiation, dosages, and adherence were studied in patients with systolic HF attending HFCs in Denmark from 2002 to 2009. Information was obtained from an electronic patient file and research database used in the HFCs combined with prescription data from the Danish Registry of Medicinal Product Statistics. A total of 8792 patients were included in the study. The mean age was 68 years; with a mean LVEF of 30%, and 72% were males. Long-term adherence to treatment was high for the patients who initiated renin-angiotensin system (RAS) inhibitors and beta-blockers. Adherence after 1 year was 93% for RAS inhibitors, 92% for beta-blockers, and 86% for spironolactone. After 3 years, it was 90% for RAS inhibitors, 88% for beta-blockers, and 74% for spironolactone. For patients referred back to their general practitioner (GP), adherence 1 year after they left the HFC was 89% for RAS inhibitors, 89% for beta-blockers, and 72% for spironolactone. CONCLUSION: In specialized outpatient HFCs, long-term adherence to RAS inhibitors and beta-blockers is close to optimal. Importantly, adherence was maintained after patients were referred back to their GP for continued management. This is likely to provide long-term benefits for the patients.