Introduction: Uterine myomas are most prevalent benign tumors in reproductive-aged women. Myomectomy is a surgical treatment for symptomatic uterine myomas for women who want to preserve fertility. Uncontrolled intraoperative bleeding with others life-threatening complications make the surgery risky even more than the hysterectomy and require a skilled surgeon, several methods have been developed to reduce this complications. Misoprostol PE1 analogue, which is recently used as treatment and prophylaxis of postpartum hemorrhage, may reduce intra-operative blood loss during abdominal myomectomies when bleeding constitutes a major problem. Aim of the work: Was to assess the effect part of a single dose of Misoprostol (400 microgram) given rectally one hour preoperative on the amount of blood loss during open Myomectomy. Patients and Methods: In a prospective randomized double-blind placebo-controlled trial which was conducted at Ain shams maternity Hospital in Cairo from October 2017 to May 2018, 50 women undergoing abdominal myomectomy for symptomatic uterine myomas were randomly divided into 2 groups : Group I (control group) consisted of 25 patients, each patient was given 2 tablets of placebo trans-rectally one hour preoperatively and without any intervention to reduce blood loss and Group II (study group) consisted of 25 patients, each patient was given 400 micrograms of misoprostol transrectally one hour preoperatively. The primary outcome was intraoperative blood loss. This clinical trial was registered in clinicaltrial.gov registry with number: NCT03483142. Results: Intra-operative blood loss was significantly lower in those women randomized to receive rectal misoprostol versus the placebo group (460.8-155.2 mL vs. 815.4 -187.7 mL). Misoprostol group showed lower mean blood loss (P<0.01) ; additionally, there was a highly significant statistical difference between Misoprostol group and placebo group as regards the postoperative hemoglobin, hematocrit concentration, operative time and IV fluid infusion during surgery (P<0.01) as Misoprostol group showed a higher postoperative hemoglobin and hematocrit concentration, and less operative time and infused IV fluid. There was no statistical significant difference between both groups as regards the blood transfusion. Conclusion: Preoperative single dose of rectal misoprostol (400 micrograms) is an effective simple method for reducing intra-operative bleeding, operative time, mean post-operative HB and Hct drop.