Objective Cancer patients use complementary and alternative medicine (CAM), but do not routinely talk about it with their clinicians. This study describes CAM discussions in oncology visits, the communication patterns that facilitate these discussions and their association with visit satisfaction. Methods 327 patients (58% female; average age 61) and 37 clinicians were recorded during an oncology visit and completed post-visit questionnaires. All CAM discussions were tagged and the Roter Interaction Analysis System (RIAS) was used to code visit dialogue. Results CAM was discussed in 36 of 327 visits; discussions were brief (< one minute), the majority patient initiated (65%) and more common for patients in early stages of cancer care. Longer visits (35 vs 29 min; p < 0.05), greater patient engagement in visit dialogue, lowered clinician verbal dominance and a more patient-centered pattern of visit communication were significantly related to visits with CAM discussions (all p values<0.01). Both patient and clinician visit satisfaction was higher with CAM discussion (p<0.05). Conclusions CAM discussions do not occur at random; they take place in visits characterized by patient-centered communication and are associated with higher visit satisfaction. Practice implications CAM discussions are perceived positively by both patients and clinicians and are facilitated by patient-centered visit communication.