PurposeMany cancer patients wish for complementary and integrative medicine (CIM) consultations led by their oncology physician. Within the KOKON‐KTO study, oncology physicians in the intervention group were trained in a blended learning to provide CIM consultations to their cancer patients in addition to distributing a leaflet about CIM websites. Control oncology physicians only distributed the leaflet. The training showed positive effects on the patient‐level. As of now, no consistent evidence exists on the long‐term effects of such one‐time‐only CIM consultation during cancer treatment.MethodsIn the KOKON‐KTO follow‐up study, cancer patients previously participating in the KOKON‐KTO study (intervention group:IG and control group: CG) received, at least 24 months later, a follow‐up questionnaire by post, evaluating long‐term effects of the KOKON‐KTO consultation using the measures provided in the original study (patient‐physician communication (EORTC‐QLQ‐COMU2), satisfaction with cancer treatment (PS‐CaTE), CIM disclosure with healthcare provider (HCP), and need for CIM consultation during cancer therapy).ResultsIn total, 102 cancer patients participated in the follow‐up study (IG n = 62; CG n = 40). The overall reponse rate was around 36% (IG: 48.4%; CG: 23.7%). In the follow‐up study, differences between groups had increased and were still shown (EORTC‐QLQ‐COMU26, 0–100 point scale, ≥10‐point‐group difference) in some subscales: patient's active behavior (in means; IG:73.6 (95% CI, 63.8–83.5); CG:61.1 (95% CI, 52.4–69.8)); clinician‐patient relationship (IG:80.9 (95% CI, 71.8–90.0); CG:68.7 (95% CI, 59.3–78.0)). For some outcomes, differences decreased over time (e.g., EORTC‐QLQ‐COMU26 subscales “takes into account patient's preference” and “corrects misunderstandings”). More patients in the CG used CIM without oncology physicians' knowledge (IG: 13.7%, CG: 24.0%).ConclusionThis study presents first findings that one‐time‐only CIM consultations may enhance patient‐physican relationship and CIM disclosure long‐term. To further support cancer patients' in their wish for CIM consultations, training programs should provide oncology physicians with CIM competencies for different cancer stages including cancer survivors.