The Chronic Disease Co-Care (CDCC) Pilot Scheme is initiated for early screening and management of people with hypertension (HT), pre-diabetes mellitus (pre-DM) and diabetes mellitus (DM) in Hong Kong. This study will evaluate the quality of care, feasibility, acceptability, effectiveness and cost-effectiveness of the Scheme. This is a 12-month cohort study among the District Health Centre (DHC) or DHC Express, healthcare providers, CDCC participants and a comparison group of 1,886 non-participants. All the person-in charge, 2 family doctors and 1 of each allied health provider from each DHC/DHC Express will be administered with the questionnaires on quality of care and costing. All CDCC participants will be included in subject characteristics, among which a convenience sample of 548 will complete a telephone survey on experience, enablement and satisfaction of the CDCC Pilot Scheme. The health outcomes of 1,886 CDCC participants and 1,886 non-participants will be compared for evaluation of effectiveness and cost-effectiveness. Participant characteristics, enablement, compliance to the standards of care, and costing of CDCC Pilot Scheme will be summarized using descriptive statistics. Differences in the proportion of patients meeting treatment targeted for HT, pre-DM and DM after 12 months will be compared by chi-squared test and logistic regressions. The incremental cost-effectiveness ratio will be evaluated by comparing with the World Health Organization (WHO) threshold. This study will inform future healthcare planning and policy for manpower and resource allocation.