Purpose: The purpose of this study was to identify the effects of nutritional education program (NEP) on nausea and vomiting, anorexia, food intake, and nutritional status among GI cancer patients undergoing chemotherapy. Methods: A nonequivalent, non-synchronized posttest design was used. Study subjects were conveniently selected 30 patients (15 subjects for each group) who were undergoing chemotherapy. The subjects of the experimental group received NEP which consisted of 2 educations and 1 counselling while they were hospitalized, and telephone counselling with nutritional supports after discharge for four times. Results: The score of anorexia was lower and the amount of food intake was higher in the experimental group than those of the control group. However, there were no significant differences in levels of nausea and vomiting, weight, hemoglobin, albumin, and total protein level between the experimental and the control group. Conclusion: The findings demonstrate that the NEP was effective in alleviating anorexia and improving subjective food intake of GI cancer patients undergoing chemotherapy. These findings suggest that NEP can be a useful nursing intervention for preventing nutritional disorders for patients with GI cancer after chemotherapy.