Complementary and alternative medicine (CAM) is widely used around the world for cancer. Preliminary research indicates that cultural factors influence cancer patients’ decisions to use, with significant associations seen between ethnicity and prevalence and type of CAM use. To enhance a culturally-appropriate understanding of CAM use in Chinese cancer patients in BC, this study explored a sample of Chinese cancer patients to gain: (1) the general conceptualization of CAM use; (2) the meaning of CAM use in relation to cancer; (3) the patterns of CAM use prior to and after cancer diagnosis; (4) the reasons for CAM use; and (5) the socio-cultural process in making decision about CAM use. A naturalistic, descriptive study design was used that incorporated semi-structural ethnographic interviewing and qualitative data analysis. The results of this study provide insights about the pattern, reasons, meaning, as well as cultural and socioeconomic factors underpinning the use of CAM. The CAM decision-making (DM) process was found to be nonlinear and comprised of four distinct phases: fitting with the cultural belief framework/lifestyle, seeking information and clarification, evaluating the effectiveness of CAM use, and balancing the cost and benefits of CAM use.