IntroductionIntegrating early detection and management of non-communicable diseases in primary healthcare has an unprecedented role in making healthcare more accessible particularly in low- and middle-income countries such as Ethiopia. This study aims to design, implement and evaluate an evidence-based intervention guided by the HEARTS technical package and implementation guide to address barriers and facilitators of integrating early detection and management of hypertension, diabetes mellitus and cardiovascular diseases in primary healthcare settings of Addis Ababa.MethodologyWe will employ a type-3 hybrid implementation-effectiveness study from November 2020 to May 2022. This study will target patients ≥40 years of age. Ten health centres will be randomly selected from each subcity of Addis Ababa. The study will have four phases: (1) Baseline situational analysis (PEN facility-capacity assessment, 150 observations of patient healthcare provider interactions and 697 patient medical record reviews), (2) Consolidated Framework for Implementation Research (CFIR) inspired qualitative assessment of barriers and facilitators (20 in-depth interviews of key stakeholders), (3) Design of intervention protocol. The intervention will have capacity enhancement components including training of non-communicabledisease (NCDservice providers, provision of essential equipment/supporting materials and monthly monitoring and feedback and (4) Implementation monitoring and evaluation phase using the RE-AIM (reach, efficacy, adoption, implementation and maintenance) framework. Outcomes on early detection and management of NCDs will be assessed to examine the effectiveness of the study.Ethics and dissemination planEthical clearance was obtained from the Addis Ababa University, College of Health Sciences Institutional Review Board and Addis Ababa Health Bureau. We plan to present the findings from this research in conferences and publish them in peer-reviewed journals.