BACKGROUND Organizational culture is considered by policy-makers, clinicians, health service managers and researchers to be a crucial mediator in the success of implementing health service redesign. It is a challenge to find a method to capture cultural issues that is both theoretically robust and meaningful to those working in the organizations concerned. As part of a comparative study of service redesign in three acute hospital organizations in England, UK, a framework for collecting data reflective of culture was developed that was informed by previous work in the field and social and cultural theory. METHODS As part of a larger mixed method comparative case study of hospital service redesign, informed by realist evaluation, the authors developed a framework for researching organisational culture during health service redesign and change. This article documents the development of the model, which involved an iterative process of data analysis, critical interdisciplinary discussion in the research team, and feedback from staff in the partner organisations. Data from semi-structured interviews with 77 key informants are used to illustrate the model. RESULTS In workshops with NHS partners to share and debate the early findings of the study, organizational culture was identified as a key concept to explore because it was perceived to underpin the whole redesign process. The Patients-People-Place framework for studying culture focuses on three thematic areas ('domains') and three levels of culture in which the data could be organised. The framework can be used to help explain the relationship between observable behaviours and cultural artefacts, the values and habits of social actors and the basic assumptions underpinning an organization's culture in each domain. CONCLUSIONS This paper makes a methodological contribution to the study of culture in health care organizations. It offers guidance and a practical approach to investigating the inherently complex phenomenon of culture in hospital organizations. The Patients-People-Place framework could be applied in other settings as a means of ensuring the three domains and three levels that are important to an organization's culture are addressed in future health service research.