Background: International knowledge exchange (iKE) offers opportunities for improvement in diabetes quality of care, through setting comparable and evidence-informed standards as well as learning from best practices. While many high-income countries (HIC) have developed diabetes quality measures, little is known on how these were exchanged and how stakeholders in low- and middle-income countries (LMIC) can benefit from and contribute to this knowledge. Aim: To analyze the current exchange of quality measures in diabetes care between countries and provide a roadmap for future improvement of quality, with emphasis on LMIC. Method: Realist synthesis, combining literature review with in-depth interviews. First, we conducted searches of electronic data-bases for peer-reviewed articles (i.e., PubMed), organizational databases (i.e., OECD iLibrary) and country-level reports. We then contacted the corresponding authors of articles and documents relevant to exchanging diabetes quality measurements between countries, and invited them to a 30–60 minutes semi-structured on-line interview on the subject. These steps were repeated iteratively by asking interviewees to recommend other key-informants or relevant studies. 383 documents were retrieved during the process. Subsequently, 80 articles and reports from 32 countries and regions contributed to the final synthesis, and 14 informants were interviewed. Results: Knowledge exchange of quality measures is conducted in two main pathways, namely country-to-country and through international organizations. On the country level, selection of measures is often based on literature reviews, Delphi consensus techniques and international workshops. The International Diabetes Federation (IDF) and the World Health Organization (WHO) have played a major role in assisting stakeholders in LMIC to estimate national diabetes prevalence and risk factors. However, according to the latest IDF Atlas, about one third of all countries still do not have satisfactory data, even for diabetes prevalence. Use of national hospital data for measuring diabetes outcomes is practiced in about one fifth of all countries and has gained momentum due to the OECD ‘Health at a Glance’ project. Nevertheless, this measurement framework is insufficient for improving primary diabetes care nor for strengthening LMIC capacity. Projects for measurement of primary diabetes care on the local/district level or within specific health plans often demonstrate efficacy, such as glycemic control, but fragmented implementation excludes patients who are not in the measured health plans. Population-wide implementation of quality measures for primary diabetes care is currently practiced in only a few high-income countries with universal health coverage. Discussion: On the country level, we suggest a roadmap for policymakers and researchers to identify which international diabetes initiatives are most appropriate in their context and what possible pathways could improve their diabetes quality measurement. Data collection and management capacities serve as barriers, and should be strengthened particularly in LMIC to achieve a global picture of diabetes care. Paradigms of ‘hospital centrality’ limit both HIC and LMIC ability to advance measurement in primary diabetes care. Population-wide and national measurement systems should be prioritized over outstanding but unsustainable projects (‘Islands of Excellence’), to achieve the desired improvement in both quality and equity of diabetes primary care.