This study investigated the utilization of clinical information on cancer to establish a basic paln for construction of systematic and efficient Cancer Clinical Information System (CCIS) in Korea. A mail survey was conducted among 141 clinical oncologists from 10 hospitals. Their utilization of the information system, capabilities in managing the information, and opinions on establishing a nationalized CCIS were surveyed and analyzed. By descriptive statistical methods, a Chi-square test, a Kruskal-Wallis test, a t-test and ANOVA. The most popular way to obtain the clinical information on cancer was through paper charts. All the respondents stated that the cancer clinical information procured from the current information system was insufficient due to the lack of standardized clinical information, the absence of coded data and applicable information, and the inefficiency of the information system. Over 90% of respondents indicated the need to develop a well organized and specifically planned CCIS. Information on diagnosis, surgery and pathology were three most useful and accessible item in clinical research on cancer. Information on side effects of cancer treatment and survival rates of cancer patient were necessary, but not available in the current CCIS. In conclusion, the existing information system has not been used effectively in extracting the requested information on clinical oncology. In order to develop a database, a higher priority should be placed on standardizing and continuously updating the contents, diversifying the search subjects and improving the security of the database system. The government needs to get involved in planning this CCIS to connect all the health care facilities across the country. Moreover, there must be some administrative support for the construction of a CCIS in order to achieve some technical advancement in hardware and software development and to regulate the clinical information.