The purpose of this study was to test the suitability of Nutritional Risk Screening 2002 (NRS 2002) among hospitalized patients and to determine the prevalence of nutritional risk, undernutrition, overweight, obesity, nutritional support and the changes of nutritional risk from admission to discharge or over a two-week period. A prospective descriptive design was used to describe patients' data collected at three Beijing teaching hospitals. A total number of 1500 consecutive patients, who met the inclusion criteria on admission and provided informed consent, were enrolled. The NRS 2002 was completed by 97.7% of all patients in this study. The overall prevalence of nutritional risk was 27.3%, the prevalence of undernutrition, overweight and obesity was 9.2%, 34.8%, and 10.2%, respectively at admission. Only 24.9% of patients who were at nutritional risk received nutritional support while 6% of non-risk patients received nutritional support. The overall prevalence of nutritional risk changed from 27.3% to 31.9% (p < 0.05), and the prevalence of undernutrition, overweight and obesity changed from 9.2% to 11.7% (p < 0.05), from 34.8% to 31.8% (p > 0.05) and from 10.2% to 8.6% (p > 0.05), respectively during hospitalization. Nutritional Risk Screening 2002 was a feasible nutritional risk screening tool in selected Beijing teaching hospitals. The prevalence of nutritional risk observed was nearly 30%. Inappropriate use of nutritional support was observed in hospitalized patients. The prevalence of nutritional risk increased in surgical patients during hospitalization.