ObjectiveTo compare the recurrence rate and risk factors between conservative surgery followed by medical treatments and conservative surgery-only in patients with focal adenomyosis. MethodsThis retrospective study was conducted in a single teaching hospital from May 2011 to October 2016. All eligible patients were identified into three groups: surgery-only group, surgery combined with gonadotropin-releasing hormone agonist (GnRHa), and a levonorgestrel-releasing intrauterine system (LNG-IUS) group. The recurrence rate and risk factors were compared among groups using Kaplan-Meier and Cox proportional hazards analyses. Receiver operating characteristic (ROC) curve analysis was applied to determine a cut-off value for identifying recurrence-related risk factors. ResultsA total of 249 postoperative patients with adenomyosis were included in the final analysis with a mean of 41 months of follow up. The recurrence rate at the long-term follow up was significantly lower in intervention groups than in the surgery-only group (P = 0.011). The Cox proportional hazards and ROC analyses showed that a menstrual cycle longer than 26 days (P = 0.026), diameter of lesions <6 cm (P = 0.030), and combination treatment using GnRHa (P = 0.039) or LNG-IUS (P = 0.007) were protective against relapse. The risk of recurrence was lower in patients with anterior (P = 0.034) or fundus (P = 0.038) adenomyosis. ConclusionPostoperative therapy using GnRHa or LNG-IUS decreases the long-term relapse rate in women undergoing conservative surgery.