Introduction There are many reasons to optimize processes in the Danish hospital system and one of the methods that have been used in many hospi-tals, are lean. Lean is a process optimization method, origi-nally developed by Toyota, which focuses on unnecessary waste in the processes and the establishment of a continuous process flow. The starting point is to create value for the customer - in our case "the patient". It surprised us that apparently healths infor-matic to support these lean processes in the hospital system haven’t been used commonly, and we therefore wanted to look at the use of health informatics in this context. Materials and Methods Our empiric has been based on a literature search, a lean project at a hospital departments and qualitative interviews of key persons from both the lean concrete project, and other lean projects in Denmark, supplemented with interviews of two providers of health IT solutions. We have made a meaningful condensation of data, which are grouped in three divisions: Implementation of lean, monitoring and proc-ess support. For analysis of the data we have chosen a theoretical framework combined with the use of change management (Kotter), Organization Culture (Schein), Socio-Technical approach (Marc Berg), STS - Symbolic interactionism (Herbert Blumer) and bound it together with Leavitts change diamond Results The result of our investigation has shown that there have been only limited use of IT in the various lean projects, and where IT have been used, it has not been incorporated as a systematic part of the lean process - but with few exceptions. We have also found that there are cultural considerations as well as some opposition to the use of IT in the clinical work in relation to lean processes. Existing IT solutions do not provide sufficient opportunities for full IT support for lean processes Discussion We have found that only limited use of health informatics and IT in relation to lean projects is launched in Danish hospitals. This can be seen as unfortunate, and perhaps even a threat to these lean projects. We have therefore outlined a number of options for the use of health informatics in lean processes. In general, we find it necessary to initially involve skills with knowledge of both health informatic technology and local IT solutions and knowledge of lean and optimization proc-esses. There is a need to focus on application of health informatics, both to identify the base, including value stream analysis for lean projects to "daily" monitoring of lean processes and to direct IT support for the specific patient trajectories, which is supported by lean processes Acknowledgments We would like to thank the staff from the hospitals and other informants who willingly answered our questions. Also thanks to our advisor, Sten Christophersen, and other mem-bers of the teaching staff at Aalborg Univer-sity who helped us along in the project process Address for correspondence Lars Henrik Søfren: SI06lhs@fc.aau.dk Aase Stegmann: SI06as@fc.aau.dk