Background: Transitions of care are high-risk periods for medicines-related harm, with almost half of medication errors in England occurring at discharge. Patients prescribed high-risk medicines—anticoagulants, antiplatelets, opioids, insulin, and cardiac therapies—are particularly vulnerable. Incident reports and patient feedback identified recurring post-discharge issues including incorrect dosing, omitted or duplicated medicines, supply failures, and poor understanding due to language or health literacy barriers. To address this, London North West University Healthcare NHS Trust (LNWH) introduced a charity-funded post-discharge medicines counselling service to improve patient safety and continuity of care. Aim: To reduce medicines-related harm after hospital discharge through structured, pharmacy-led post-discharge counselling for patients prescribed high-risk medicines. Method: Eligible patients were identified at discharge via CERNER and contacted by a medicines management pharmacy technician, with pharmacist oversight for complex cases. Consultations reviewed medication changes, reinforced safety messages, assessed understanding, and resolved clinically significant medicines-related issues. Data included patients contacted, interventions made, and qualitative feedback. Results: Between August 2024 and January 2026, 1,995 patients were contacted. Interventions were required in 588 patients (29.5%), addressing incorrect anticoagulant dosing, duplicate therapy, inappropriate treatment duration, non-adherence, and supply failures. A further 870 patients (43.6%) required no intervention but benefited from reassurance and reinforcement of safety advice. Patient satisfaction exceeded 99%, with feedback highlighting improved confidence and understanding of medicines at home. Conclusion: Pharmacy-led post-discharge counselling identifies and resolves medicines-related issues early, improves patient understanding, and offers a scalable model for safer transitions of care.