As use of complementary medicine (CM) is increasing, health professionals may require proper training in CM to offer evidence-based advice to their patients. The aim of this study was to explore interprofessional collaboration (IPC) in CM in order to gain a comprehensive overview of determinants and to facilitate the definition of objectives for an undergraduate interprofessional educational module. Pursuant to a sequential mixed-methods approach, focus groups and individual interviews with health professionals, who actively use CM in patient care, were conducted. All hospital employees at the University Hospital Lübeck, Germany, were asked to complete an online questionnaire that was based on the previously obtained qualitative results. The interviews with 20 participants revealed four main themes: professionspecific aspects, communication, health care system-associated factors, and the influence of CM on interprofessional dynamics. An analysis of the 157 responses in the online questionnaire showed that team meetings (n = 124, 79%) were most frequently stated as promoting IPC. In binary regression analyses, nursing ) and medical professions ) predicted evidence-based care as enabler for IPC. Hence, teaching professional competencies and an equal understanding of evidence-based medicine seems necessary to promote IPC within CM.