Background:Arnica Montana is used for treating wounds and injuries on account of its supposed abilities to control pain, bruising, reduce swelling and promote recovery. It is one of the widely used homeopathic preparations and is popular with patients undergoing surgery.Aim of work:The efficacy of homeopathy is still under debate. The objective of this study was to evaluate the efficacy of homeopathic arnica in reducing the pain following abdominal hysterectomy.Methodology:Randomized placebo controlled trial at Al-Kasr Al-Ainy. 60 patients under age of 60 undergoing abdominal hysterectomy were randomized into intervention and control groups receiving either Arnica 200C or identical placebo, two tablets of Arnica 200C or placebo were taken sublingually one hour preoperatively then two tablets every two hours on the first postoperative day and then two tablets twice daily were taken from the second day to the seventh day postoperatively.Results:60 patients completed the study. The Arnica group had more drop in pain score throughout the study but was statistically insignificant (p value = 0.137). The two groups did not differ significantly on blood pressure or heart rate.Conclusion:We conclude that Arnica Montana has no advantage over placebo in reducing postoperative pain in patients undergoing abdominal hysterectomy.