Background: Nutritional support for surgical care is crucial because hospital malnutrition is rather common. However, low- and middle-income countries have not adequately addressed nutritional management of surgical patients. To highlight need for nutritional management in surgical patients, the present study aimed to describe preoperative nutritional status in patients who underwent gastrointestinal cancer surgery in Vietnam and to investigate the relationship between preoperative malnutrition and adverse outcomes, such as postoperative complications and prolonged length of hospital stay., Methods: We reviewed medical records of patients who underwent a major curative surgery for gastrointestinal cancer at the national hospital in Ho Chi Minh City, Vietnam. We identified preoperative malnutrition based on body mass index and serum albumin level, and postoperative complications in the first 30 d postoperative. We estimated the relative influence of malnutrition on complications and length of hospital stay using multivariate regression models., Results: Of 459 eligible patients, 63% had colorectal cancer, 33% gastric cancer, and 4% esophageal cancer. The prevalence of malnutrition was 19%. No patients died during hospitalization; however, 26% developed complications after surgery. The average length of hospital stay was 14 d. After controlling for potential confounders, preoperative malnutrition was associated with an increased risk of postoperative complications (odds ratio = 1.97) and prolonged hospital stay (2.8 d)., Conclusions: Preoperative malnutrition affects surgical outcomes among patients with gastrointestinal cancer in Vietnam. We recommend implementing preoperative nutritional interventions to achieve better outcomes among surgical cancer patients., (Copyright © 2017 Elsevier Inc. All rights reserved.)