BackgroundThe preservation of fertility and integrity of the reproductive organs has increasingly been of concern to most women with adenomyosis. Adenomyomectomy is conservative surgery that is now widely applied; however, relapse is a serious problem after the operation. Postoperative treatment, such as gonadotropin-releasing hormone agonist (GnRHa) has been suggested to result in reducing the rate of disease recurrence. However, there is still a lack of evidence from randomized clinical trials examining the efficacy of GnRHa in decreasing the postoperative recurrence rate.Method/designRelapse after conservative surgery combined with triptorelin acetate versus conservative surgery only in women with focal adenomyosis is a multicenter, prospective, randomized controlled trial. The primary outcome is relapse assessed using a visual analogue scale (VRS) and numeric rating scale (NRS), pictorial blood loss assessment chart (PBAC) score, and the size of the uterus and the lesion as measured by two/three-dimensional color doppler ultrasonography (2D/3D-CDUS) or magnetic resonance imaging (MRI). The secondary outcomes include quality of life, clinical pregnancy, ovarian reserve, adverse events, assessment by the Short Form (36) Health Survey and Female Sexual Function index, serum follicle-stimulating hormone, estradiol levels, and anti-Muellerian hormone and so on. All these indexes are measured at 3, 6, 12, 18, 24, 30, and 36months after conservative surgery.DiscussionThe result of this large, multicenter randomized trial will provide evidence for one of the strategies of long-term management in focal adenomyosis after conservative operation.Trial registrationChinese Clinical Trial Registry: ChiCTR1800014340. Registered on 6 January 2018.