Introduction Leiomyoma recurrence is a major concern for long-term myomectomy management, especially for multiple leiomyomas. Gonadotropin-releasing hormone agonist (GnRHa) is one of the most effective medications to reduce the volume of fibroids and the uterus. However, its role in preventing recurrence after conservative surgery remains unclear. At present, there is no randomised clinical trial determining the efficacy of GnRHa treatment for preventing multiple leiomyomas recurrence after myomectomy. Methods and analysis We are conducting a phase IV randomised controlled trial in women aged 18-45 undergoing myomectomy for multiple leiomyomas. After surgery, women whose pathological result confirms multiple leiomyomas are randomised in a 1:1 ratio into an observation or GnRHa group. The primary outcome is the recurrence of either clinical symptoms or fibroids on imaging. Patients will be assessed for adverse events during the follow-up. Ethics and dissemination The study was approved by the Medical Ethics Committee of the Tongji Hospital Affiliated with the Tongji Medical College of Huazhong University of Science and Technology (TJ-IRB20180311) according to the submitted study protocol (V.1.0, 10 November 2017) and informed consent (V.1.0, 10 November 2017). The results will be presented at domestic and international conferences and published in peer-reviewed journals.