Background To address the rising non-communicable diseases (NCDs) in Malaysia, the Better Health Programme Malaysia (BHP MYS) engaged and trained community health volunteers (CHVs) to undertake health promotion activities with poor urban communities in Kuala Lumpur to reduce their NCD risk. This study evaluates the extent that the capacity-building programme achieved the objectives of increasing knowledge and confidence in NCD prevention and adopting personal lifestyle changes. Methods A capacity-building programme was designed to emphasise active learning approaches and blended learning (in-person and digital) and was delivered between January to December 2021 (during the Malaysian Government “Movement Control Orders” in response to the COVID-19 pandemic). Thirty CHVs participated in the capacity-building programme. A mixed methods evaluation approach was used, including quantitative surveys and routine data, focus group discussions, and semi-structured interviews. Findings Community Health Volunteers increased their NCD knowledge (85.2% provided correct answers in post-programme assessment compared to 43.3% at pre-programme assessment), made changes to their dietary and physical activity practices (100%), and adopted new engagement techniques, particularly a digital social influencer role for NCD behaviour change. The most important factors for sustaining participation were individual motivation and a supportive environment. CHVs were satisfied with the blended in-person-digital approach and perceived that the usefulness and applicability of the health information received was the primary benefit across all delivery modes. Cohort-based, active learning approaches and actionable messages can encourage learning retention and facilitate application. Dedicated technical support and ‘job aid’ tools are required for CHVs to perform and sustain NCD prevention roles effectively. Conclusions The capacity-building programme effectively increased CHV capacities to address NCDs in their own lives and communities and was acceptable to CHVs. The findings suggest the value of cohort-based, active learning approaches in building capacity. Expanding on capacity-building and sustaining involvement are important considerations for this cohort and, in general, for health volunteer capacity-building in Malaysia and elsewhere.