INTRODUCTION AND OBJECTIVE: This paper provides an overview of the DUQuE (Deepening our Understanding of Quality Improvement in Europe) project, the first study across multiple countries of the European Union (EU) to assess relationships between quality management and patient outcomes at EU level. The paper describes the conceptual framework and methods applied, highlighting the novel features of this study. DESIGN: DUQuE was designed as a multi-level cross-sectional study with data collection at hospital, pathway, professional and patient level in eight countries. SETTING AND PARTICIPANTS: We aimed to collect data for the assessment of hospital-wide constructs from up to 30 randomly selected hospitals in each country, and additional data at pathway and patient level in 12 of these 30. MAIN OUTCOME MEASURES: A comprehensive conceptual framework was developed to account for the multiple levels that influence hospital performance and patient outcomes. We assessed hospital-specific constructs (organizational culture and professional involvement), clinical pathway constructs (the organization of care processes for acute myocardial infarction, stroke, hip fracture and deliveries), patient-specific processes and outcomes (clinical effectiveness, patient safety and patient experience) and external constructs that could modify hospital quality (external assessment and perceived external pressure). RESULTS: Data was gathered from 188 hospitals in 7 participating countries. The overall participation and response rate were between 75% and 100% for the assessed measures. CONCLUSIONS: This is the first study assessing relation between quality management and patient outcomes at EU level. The study involved a large number of respondents and achieved high response rates. This work will serve to develop guidance in how to assess quality management and makes recommendations on the best ways to improve quality in healthcare for hospital stakeholders, payers, researchers, and policy makers throughout the EU.