Patient-controlled analgesia (PCA) has been widely used for postoperative pain control in medical surgery parts. Conventional intramuscular analgesia (IMA) is also effective in postoperative pain control, but it has some disadvantages that depend on patients'perception of pain and the anxiety that they endure caused by the delay of the injection time. This study was conducted to assess the efficacy and postoperative outcomes of intravenous PCA compared to IMA injections in 36 patients (BSSRO). Three factors were compared: amount of pain in PCA and IMA group ; amount of pain according to the sex in PCA and IMA group and the amount of pain according to the analgesia use. Results of this study did not demonstrate a statistically significant difference in any of these, using a p value of 0.05. The results of this study were as follows: 1. There was no statistically significant difference in VAS pain score between IMA group and PCA group. 2. There was no statistically significant difference according to the sex. 3. There was no statistically significant difference according to the amount of PCA. The history of PCA is about 30 years and many literatures have reported about its effects, complications, methods, advantages and disadvantages. So, this study has some limitations of small sample size to conclude the effects of PCA. But when the decision about the method for postoperative pain control has to be made, it should be made based on patient or physician preference and cost factors rather than on the trend.