introductionGeneral practitioners (GPs) routinely provide care for patients with heart failure (HF); however, adherence to management guidelines, including titrating medication to optimal dose, can be challenging in this setting. This study will evaluate the effectiveness of a multifaceted intervention to support adherence to HF management guidelines in primary care. METHODS AND ANALYSIS: We will undertake a multicentre, parallel-group, randomised controlled trial of 200 participants with HF with reduced ejection fraction. Participants will be recruited during a hospital admission due to HF. Following hospital discharge, the intervention group will have follow-up with their GP scheduled at 1 week, 4 weeks and 3 months with the provision of a medication titration plan approved by a specialist HF cardiologist. The control group will receive usual care. The primary endpoint, assessed at 6 months, will be the difference between groups in the proportion of participants being prescribed five guideline-recommended treatments; (1) ACE inhibitor/angiotensin receptor blocker/angiotensin receptor neprilysin inhibitor at least 50% of target dose, (2) beta-blocker at least 50% of target dose, (3) mineralocorticoid receptor antagonist at any dose, (4) anticoagulation for patients diagnosed with atrial fibrillation, (5) referral to cardiac rehabilitation. Secondary outcomes will include functional capacity (6-minute walk test); quality of life (Kansas City Cardiomyopathy Questionnaire); depressive symptoms (Patient Health Questionnaire-2); self-care behaviour (Self-Care of Heart Failure Index). Resource utilisation will also be assessed. ETHICS AND DISSEMINATION: Ethical approval was granted by the South Metropolitan Health Service Ethics Committee (RGS3531), with reciprocal approval at Curtin University (HRE2020-0322). Results will be disseminated via peer-reviewed publications and conferences. TRIAL REGISTRATION NUMBER: ACTRN12620001069943.