Background: Postoperative shivering is a complication of general anesthesia. Shivering increases cardiac output, oxygen demand, and postoperative surgical incision's pain.

  Objective: The aim of this study was to evaluate the effect of Diclofenac Na suppository on postoperative shivering.

  Methods: This was a case-control study performed on 140 women who were divided into two equal groups of 70 members each and marked as case and control groups. The case group received diclofenac Na supp 100mg, ten minute before the induction of anesthesia whereas the control group was given no such medication. Axillary temperature was measured before the induction and 1 hr after the extubation. Data were analyzed by SPSS and chi-square test.

  Findings: The incidence of shivering in case and control groups were (%27.1) and (%48.1), respectively. There was a significant difference between two groups (P=0.014). The mean temperature changes in case and control groups were (-0.18º^C±0.02º^C) and (-0.29º^C±0.029º^C), respectively. The difference between two groups was found to be significant, statistically (P=0.004).

  Conclusion: Our findings showed that diclofenac Na supp has the potential to effectively decrease the postoperative shivering while maintaining the body temperature more stable.