This volume presents the papers from the fourth International Conference on Information Technology in Health Care: Socio-technical Approaches held in Aalborg, Denmark in June 2010. In 2001 the first conference was held in Rotterdam, The Netherlands with the theme: Sociotechnical' approaches that consider 'social' and 'technical' aspects as inextricably intertwined, and as equally important in information systems design, implementation and evaluation. The second conference was held in 2004 in Portland, Oregon, USA. The theme here was: To err is system. Sydney in Australia was the venue for the third conference with the theme: The ability to design, implement and evaluate safe, useable and effective systems within complex health care organizations. The theme for this conference was "Designing and Implementing Health IT: from safe systems to patient safety". The contributions have reflected on a number of important issues. How are the mutual adaptations of technology and work practice during implementation reflected in design and redesign? How are the successful implementations carried out as a process of organizational change? How does a socio-technical understanding improve the design and implementation of safe systems and thus contribute to the agenda of patient safety? The contributions demonstrate how the health informatics community has contributed to the performance of significant research and to translating research findings to develop health care delivery and improve patient safety. The editors want to thank Marianne Sørensen, Aalborg University for keeping track of all the contributions and ensuring they found their way to the final proceedings. We also want to thank all the reviewers for their excellent work in providing constructive feedback to the authors. This valuable input has significantly improved the quality of many papers. We also want to acknowledge the sponsorship of the conference by Det Obelske Familiefond, the Mayor of Aalborg and of Aalborg University.