Objectives: The aim of this study was to examine the role of complementary and alternative medical (CAM) practitioners in integrative practices where general practitioners (GPs) and CAM practitioners were co-located. Design: This study used grounded theory, a qualitative methodology from the interpretive paradigm. Setting: A total of 23 integrative practitioners (10 general practitioners and 13 naturopaths) were interviewed. The informants were drawn from 16 integrative practices and one non-integrative general medical practice. Results: In 11 out of 16 integrative practices the CAM practitioners yielded their primary contact role to the GPs. CAM practitioners were restricted to expanding the range of treatment options available to patients. However, the role of the CAM practitioners was influenced by the level of CAM training the GP(s) in the practice had undertaken. The more CAM training the GPs had undertaken, the more CAM practitioners were enlisted as diagnosticians as well as treatment providers. Conclusion: CAM practitioners in integrative practices had an accessory role to the GPs in the practice, deferring diagnosis and assessment activities to the GPs. However, where GPs had significant training in CAM, the CAM practitioner's role included both treatment and diagnostic activities.