We investigated the effect of non-steroidal anti-inflammatory drugs (NSAIDs) on upper gastrointestinal(GI) disorders in orthopaedic patients. Among a total of 1,923 patients (946 men and 977 women, mean age: 53 years) who received NSAIDs, 486 patients (25%) experienced some adverse reactions including mild GI symptoms, 364 patients (19%) had gastric mucosal lesion, and 37 patients (2%) had gastric ulcer. The number of patients with upper GI disorders was significantly higher in patients aged 50 years or older, than those under 50 years. Irrespective of the kinds of NSAIDs applied, our results suggest an increased risk of adverse effect causing upper GI disorders in orthopaedic patients who are administered NSAIDs for a long-term.