This study was performed to investigate small area variation in rates of three common surgeries in general surgery department across 156 small areas. Three surgery rates were analyzed; Anal and/or stomal procedures, inguinal and/or femoral hernia procedures, appendectomy. Methods: We used health insurance claims data and the number of patients were 13,845, 2,154 and 7,151 persons respectively. Surgery rates were directly standardized with age and sex and logistic regression was used to analyze surgery rates. Results: Mapping of the surgery rates, there was small area variation in anal and/or stomal procedures. The clinic which was located in more competitive market and chose DRG payment system tends to do more anal and/or stomal procedures. There was no factor except DRG bed rates had effect on rate of inguinal and/or femoral hernia procedures. Conclusions: Findings of this study will contribute to developing investigation method on small area variation and policy to reduce the variation such as developing evidence based medical practice guideline.