Objective To investigate prevalence of nutritional risk, undernutrition, and nutritional support of hospitalized patients with non-tuberculosis mycobacteria. Methods Adult patients in Guangzhou Chest Hospital from October 2012 to October 2014 were enrolled by fix-point consecutive sampling. Nutritional Risk Screening 2002 (NRS2002) was performed and nutritional support was evaluated in all patients. Results A total of 402 patients were enrolled.Overall prevalence of undernutrition was 35.8%, and nutritional risk was 66.7%. Among all the patients, the rate of nutritional support was 60.0%, including 82.1%of patients with nutritional risk and 15.7% of non-risk patients. Gerontal patients, retreatment patients and female patients are in the greater possibility of being expose to nutritional risk or undernutrition. Conclusion A large proportion of inpatients with non-tuberculosis mycobacteria were at nutritional risk or undernutrition.The application of parenteral or enteral nutritional support currently maybe inappropriate. NRS2002 and parenteral or enteral nutrition guideline are required to affording nutritional support.