Health systems worldwide struggle to manage the growing burden of type 2 diabetes and hypertension. Many patients receive suboptimal care, especially those most vulnerable. An evidence-based Integrated Care Package (ICP) with primary care-based diagnosis, treatment, education and self-management support and collaboration, leads to better health outcomes, but there is little knowledge of how to scale-up. The Scale-up integrated care for diabetes and hypertension project (SCUBY) aims to address this problem by roadmaps for scaling-up ICP in different types of health systems: a developing health system in a lower middle-income country (Cambodia); a centrally steered health system in a high-income country (Slovenia); and a publicly funded highly privatised health-care health system in a high-income country (Belgium). In a quasi-experimental multi-case design, country-specific scale-up strategies are developed, implemented and evaluated. A three-dimensional framework assesses scale-up along three axes: (1) increase in population coverage; (2) expansion of the ICP package; and (3) integration into the health system. The study includes a formative, intervention and evaluation phase. The intervention entails the development and implementation of an improved scale-up strategy through a roadmap with a minimum dataset to monitor proximal and distal outcomes. The SCUBY project is expected to result in three different roadmaps, tailored to the specific health system and country context, to progress scale-up of the ICP along three dimensions. These roadmaps can be adapted to other health systems with similar typology. Implementation is expected to increase the number of well-controlled patients with type 2 diabetes and hypertension in Cambodia, to reduce inequities in care and increase patient empowerment in Belgium and Slovenia.