OBJECTIONS: To investigate the utilization patterns of non-steroidal anti-inflammatory drugs (NSAIDs) among the elderly with osteoarthritis (OA) undergoing primary ambulatory care in Busan metropolitan city, Korea. METHODS: OA patients, aged 65 years and over, were identified from the Korean National Health Insurance Review Agency drug prescription database. The subjects had at least one episode of claim for OA (ICD-10-CM: M15-M19) between August 1, 2000 and February 28, 2002. Trends in the determinations of NSAIDs utilization were identified using chi-squared tests for trend. RESULTS: There were 47, 711 osteoarthritic patients. The total number of visits by these patients was 177, 443, with a total frequency for NSAID prescriptions of 214, 952. Seventy-nine percent of the OA patients were female. NSAIDs were prescribed on 133, 284 visits (75.1%) and the proportion of prescriptions was significantly increased with age. Only the proportion of visit when NSAIDs were prescribed decreased, from 65.1 to 43.5%, during the study period (p< 0.001). However, the proportion of combined treatments with anti-ulcer drugs was increased. The use of NSAIDs injections was decreased. Of the individual NSAIDs, diclofenac (28.7% of total frequency of NSAID prescriptions), piroxicam (15.0%) and talniflumate (8.7%), were the most frequently prescribed. Among the NSAIDs prescribed OA visits, 45.7% used two or more NSAIDs. CONCLUSION: The total proportion of NSAIDs prescribed to the osteoarthritic patients was higher than in other studies. The decline in the use of NSAIDs during the study period, and the frequent selection of safer medications, such as combination therapy with anti-ulcer drug, may reflect the risk awareness of the use of NSAIDs.