The purpose of this paper is to examine the current state of open source projects in health care environment and the level of collaboration in this field. We underpinned our discussion on the theoretical foundations of institutional theory, collaboration and virtual organisations. This article reports briefly the challenges of health care information systems and open source software as a possible solution alternative. The empirical part analyses an EU sponsored open source health care project, SPIRIT. We argue that both interorganisational HCIS and OSS development projects face similar challenges in collaboration due to their organisational setting. To enhance future collaboration, we introduce a set of managerial solutions found in successful open source projects.