BACKGROUND: The Community Oriented Substance Use Programme (COSUP) is the first publicly funded, community-based programmatic response to the use of illegal substances in South Africa. It is founded on a systems thinking, public health and clinical care harm reduction approach. AIM: To describe the critical components, key issues and accomplishments in the initiation and delivery of evidence-based, community-oriented, substance-use health and care services. SETTING: The Community Oriented Substance Use Programme is implemented by the University of Pretoria in four of seven Tshwane Metropolitan Municipality regions. METHODS: Quantitative and qualitative data were extracted and triangulated from plans, reports, minutes and other documents. RESULTS: Between 2016 and 2019, COSUP engaged in national and local policy and guidelines development. In Tshwane, it created practical working relations with 169 organisations and institutions and set up 17 service sites. These provide counselling, linkage to care and opioid substitution therapy services to 1513 adults (median age of 30 years), most of whom are male (90%), with similar proportions of clients who smoke (51%) or inject (49%) heroin. It also offers needle and syringe services (approximately 17 000 needles distributed/month) and has built human resource capacity in harm reduction among staff, clients and personnel in partner organisations. CONCLUSION: The Community Oriented Substance Use Programme offers an evidence-based, public-health informed, feasible alternative to an abstinence-based approach to substance use. However, to translate the programme's achievements into sustainable outcomes at scale requires health system integration; generalist, patient-centred care; affordable medication in a comprehensive package of harm reduction services; multisectoral partnerships; systematic, continuous capacity development; financial investment; and sustained political commitment.