Background: Reports of questionable or detrimental research practices (QRPs) call into question the reliability of scientific evidence and the trustworthiness of research. A critical component of the research ecosystem is the organization within which research takes place. We conducted a survey to explore the attitudes and beliefs of European and American researchers about the organisations in which they work, their own research practices and their attitudes towards research integrity and research integrity policies. Methods: We administered an online survey (International Research Integrity Survey (IRIS)) to 2,300 active researchers based in the US and 45,000 in Europe (including UK, Norway, Iceland and Switzerland). We employed a stratified probability sample of the authors of research articles published between 2016 and 2020 included in Clarivate’s http://www.webofscience.com Web of Science citation database. Coverage includes researchers in the humanities, social sciences, natural sciences and medical sciences, who hold at least a master’s level degree. Results: In comparison to researchers in the US, European researchers admit to more QRPs and are less confident in maintaining high research integrity (RI) standards. In the US and Europe, many researchers judge their organization to fall short of best RI practice. All researchers recognize the benefits of RI, reliable knowledge and the trust of colleagues and the public, and there is support for RI training particularly among Europeans. Conclusion: To create and maintain a culture of integrity in scientific research, a collective commitment from researchers, their institutions and funders is needed. Researchers rely on many channels of communication about research integrity and thus the involvement of many different participants in the research system is required to make improvements. Policies must be developed to reinforce best practice rather than being seen as an irrelevance to the real business of research.