AIM: To assess the effects of poor nutritional and psychological status on tolerance of cancer treatment and the recovery of physical performance status in patients with gastrointestinal cancer.METHODS: An epidemiological survey with respect to nutritional and psychological status in patients with gastrointestinal cancer was conducted among 182 operated patients in four provincial-level hospitals from December 2005 to June 2006. The food frequency survey method, state-trait anxiety inventory (STAI) and depression status inventory (DSI) were used to obtain information about the diet and psychological status in the patients. Nutritional status in the participants was reflected by serum albumin (Alb), hemoglobin (HB) and body mass index (BMI).RESULTS: Alb, protein intake and anxiety were associated with the severity of side effects of treatment.The adjusted relative risk (RR) for Alb, protein intake and anxiety was 3.30 (95% CI: 1.08, 10.10, P = 0.03), 3.25(95% CI: 1.06, 9.90, P = 0.04) and 1.48 (95% CI: 1.29,1.70, P ＜ 0.0001), respectively. Moreover, calorie intake,HB and depression were associated with the recovery of physical performance status in the patients. Adjusted relative risk was 2.12 (95% CI: 1.09, 4.03, P = 0.028),2.05 (95% CI: 1.08, 3.88, P =0.026) and 1.07 (95% CI:1.02, 1.12, P = 0.007), respectively.CONCLUSION: Both poor nutrition status and psychological status are independent risk factors for severe side effects of cancer treatment, and have impact on the recovery of physical performance status in patients after treatment.