Objective To explore the effectiveness of "Internet Plus" nutrition education on the nutritional status of patients with digestive tract malignancies undergoing chemotherapy, and to find out effective method for improving nutritional status of patients. Methods Ninety patients with gastric cancer or colorectal cancer who received the first treatment of adjuvant chemotherapy were recruited and divided into two groups according to their ward. The control group (n=44) received conventional nutrition education, while the intervention group was given "Internet Plus" nutrition education. The levels of nutrition knowledge, attitudes and practice (KAP), as well as nutritional status of patients in both groups were assessed before and immediately after the 3-month intervention. Results The intervention group had significantly higher nutrition KAP, the Patient-Generated Subjective Global Assessment score, body mass index, hemoglobin and serum albumin compared to the control group immediately after the intervention (all P<0.05). Conclusion Implementation of "Internet Plus" nutrition education for patients with digestive tract malignancies can improve their nutrition KAP and nutritional status.