Sustainable IT operation and maintenance through user participation in design and implementation of IT-systems in health care, is only secured if informal and formal knowledge are equally recognized. The paper argues that informal situated knowledge is of significance for the individual health care worker's performance. The concept indigenous knowledge is analyzed as a subset of informal knowledge and reference is made to the concepts of social capital and cultural capital. Finally, an approach rooted in Participatory Learning and Action methods is recommended as a technique for involving staff in IT-system design for technological change.