Introduction: Laparoscopic myomectomy can be difficult when fibroids are large and numerous. This may result in extensive intraoperative bleeding and the need for a conversion to a laparotomy. Medical pretreatment prior to surgery might reduce these risks by decreasing fibroid size and vascularization of the fibroid. We compared pretreatment with ulipristal acetate (UPA) vs gonadotropin-releasing hormone agonists (GnRHa) prior to laparoscopic myomectomy on several intra- and postoperative outcomes. Material and methods: We performed a non-inferiority double-blind randomized controlled trial in nine hospitals in the Netherlands. Women were randomized between daily oral UPA for 12 weeks and single placebo injection or single intramuscular injection with leuprolide acetate and daily placebo tablets for 12 weeks. The primary outcome was intraoperative blood loss. Secondary outcomes were reduction of fibroid volume, suturing time, total surgery time and surgical ease. Results: Thirty women received UPA and 25 women leuprolide acetate. Non-inferiority of UPA regarding intraoperative blood loss was not demonstrated. When pretreated with UPA, median intraoperative blood loss was statistically significantly higher (525 mL [348-1025] vs 280 mL[100-500]; P = 0.011) and suturing time of the first fibroid was statistically significantly longer (40 minutes [28-48] vs 22 minutes [14-33]; P = 0.003) compared with GnRHa. Pretreatment with UPA showed smaller reduction in fibroid volume preoperatively compared with GnRHa (−7.2% [−35.5 to 54.1] vs −38.4% [−71.5 to −19.3]; P = 0.001). Laparoscopic myomectomies in women pretreated with UPA were subjectively judged more difficult than in women pretreated with GnRHa. Conclusions: Non-inferiority of UPA in terms of intraoperative blood loss could not be established, possibly due to the preliminary termination of the study. Pretreatment with GnRHa was more favorable than UPA in terms of fibroid volume reduction, intraoperative blood loss, hemoglobin drop directly postoperatively, suturing time of the first fibroid and several subjective surgical ease parameters.