Methods This study will adopt a non-randomised intervention cohort design (i.e. controlled before-and-after (CBA) study). Patients admitted to hospital with an ACS will be recruited for this study. Patients must be prescribed medicines for secondary prevention. The study will be delivered by hospital pharmacists over two sessions and will target both intentional (Session 1) and unintentional (Session 2) adherence barriers. Session 1 will involve eliciting and challenging patients' erroneous beliefs about medications. Session 2 will involve formulating specific action plans to encourage medication-taking habit formation.