Multilocular cystic leiomyomas rarely develop following myomectomy. To the best of our knowledge, there are no published reports on recurrent multilocular cystic leiomyoma following myomectomy. We here present such a case. A 45-year-old woman visited our outpatient clinic because of heavy vaginal bleeding. She underwent laparoscopic myomectomy for a solid mass in the uterine cavity. Subsequent pathological examination of the operative specimen revealed a tumour with well-demarcated borders and spindle cells arranged in intersecting fascicles. Seven days postoperatively, ultrasonography revealed a cystic lesion. Magnetic resonance imaging performed 28 months postoperatively revealed a large, well-defined, multilocular cystic mass that was homogeneously hyperintense on T2-weighted images on the exterior of the uterus. Abdominal hysterectomy was performed. On pathological examination of the operative specimen, she was found to have a leiomyoma with marked cystic degeneration. Incomplete excision of a multilocular cystic leiomyoma may result in recurrence in the form of a large cystic mass. Clinical differentiation between a multilocular cystic leiomyoma and an ovarian tumour may be difficult. Complete resection of a uterine multilocular cystic lesion prevents recurrence.