Objectives : Combined treatment (CT) of oriental herbal medicine and prescribed drugs is now being increasingly used among cancer patients around the world. However, in Korea, clinical information on the frequency, efficacy and safety of CT among cancer patients has not yet been thoroughly reported. This study aimed to identify the status and adverse effects of CT for the management of cancer patients. Methods : A questionnaire and medical record survey by oriental medical doctors or physicians were performed at two oriental medical hospitals and one general hospital. Of the initial 400 in-patients, 368 participated in this survey, representing a response rate of 92.0%. Results : Among cancer patients in oriental medical hospitals, the proportion of CT was 45.9%. In contrast, the proportion of CT in the general hospital was only 0.6%. The proportion of CT among breast cancer patients (20) and gastric cancer patients (35) were 85.0% and 51.4%, respectively. The proportion of CT among cancer patients was high in younger, female or married patients groups. 10 respondents (11.1%) among 90 cancer patients experienced several adverse effects including nausea, fatigue, etc. Conclusions : This study suggests that many more patients in oriental medical hospitals than general hospitals use combined treatment of oriental herbal medicine and prescribed drugs for management of cancer. Therefore, medical professionals should provide comprehensive and up-to-date clinical information about potential benefits and risks of CT to cancer patients in Korea.