Purpose: The purpose of this study was to investigate the actual conditions of the functional foods used by elderly patients with digestive system cancers. Methods: The sample consisted of 105 elderly patients with digestive system cancers who attended an outpatient clinic after be diagnosed and had undergone medical treatment for digestive system cancers. Structured questionnaires were used to collect the data and data collection was done from April 1 to May 1, 2009. The data were analyzed using frequency, percentage, mean, and Fisher's exact test. Results: For the patients, 78.1% used functional health foods. The most frequently used were vitamins and minerals, 40.7%, followed by Terpenes including steamed red ginseng and ginseng 17.7%. On effects of the functional health foods, 41.5% said that they have little effect, 27.7% said no effect , and 23.7% said considerable effect . For medical workers, 45.6% reject the use of functional health foods, 33.6% accepted them and 20.8% recommended them. Medical workers who recommended selenium and lycopen, and accepted vitamin A, C, E and steamed red ginseng, rejected glucosamine and mushrooms. Conclusion: Education and consultation are needed to prevent misuse of functional health foods and damage of from using them.