Background: Tumor morcellation happened to facilitate iatrogenic metastasis for patients with occult uterine sarcoma. The optimal completion surgery for these patients needed to be established. Methods: Data were retrospectively collected and analyzed from patients with occult uterine sarcoma undergoing morcellation. Results: 19 consecutive patients with uterine sarcomas undergoing morcellation were accessed between January 2008 and December 2018, including 12 patients with uterine leiomyosarcoma and 7 with endometrial stromal sarcoma. Compared with a simple hysterectomy and individualized surgical resection for suspicious extra-uterine lesions, cytoreduction was significantly associated with a lower recurrence rate (p = 0.017), and none of the seven patients undergoing cytoreduction suffered a recurrence. However, the interval between the initial operation and re-operation, transabdominal route (laparoscopic vs. open surgery), and adjuvant therapy had no such significant difference. Conclusions: Cytoreduction was considered as the optimal completion surgery for patients with occult uterine sarcoma undergoing morcellation.