Purpose: The purposes of this study were to identify and compare various types of post operative pain management and the costs for pain management following 4 different types of surgery. Methods: Data were collected from 325 medical charts which were extracted from the billing databases of a tertiary hospital and analyzed using numbers, percentages, one way ANOVA, and Scheff$acute{e}$ test. Results: For pain management, 10.5% of patients used PCA only, but the other patients combined other methods with PCA. The average length of PCA use was significantly different by operation. Almost one third (32.9%) of patients experienced at least one of side effects due to analgesics used for pain management, with highest incidence being for nausea and vomiting. For patients who underwent a total abdominal hysterectomy, 34.7% used PCA less than 2 days due to side effects of the analgesics and the ratio of analgesia cost to total hospital cost and total pharmacy cost were highest compared to other operations. Conclusion: The results of this study indicate a need to develop new strategies to more effectively manage postoperative pain to decrease incidences of side effects without increasing medical costs.