The purpose of this study was to evaluate the impact of tumor morcellation on the outcomes of patients with apparently early low-grade endometrial stromal sarcoma (LGESS). Outcomes were retrospectively compared between patients with apparently early LGESS who did not (group A, n = 27) or did (group B, n = 23) undergo tumor morcellation. There were no between-group differences in age, menopausal status, parity, body mass index, and preoperative presumptive diagnosis, nor were there between-group differences in tumor stage, tumor size, myometrial invasion, lymphovascular space invasion, frequency of ovarian preservation, adjuvant therapy, or follow-up time. More patients in group A underwent lymph node dissection (51.9 vs. 21.7%; P = 0.029). Only 1 patient in each group had distant recurrence. There were 2 patients (7.4%) in group A and 7 (31.4%) in group B who had abdominopelvic recurrence. The risk of abdominopelvic recurrence was significantly higher in group B than in group A (odds ratio [OR], 5.47; 95% confidence interval [95% CI], 1.04-29.70; P = 0.035). The 5-year disease-free survival (DFS) rates were 84% for group A and 55% for group B (P = 0.028) and the 5-year abdominopelvic DFS rates were 89 and 58% (P = 0.023), respectively. Multivariate analysis showed that tumor morcellation were significantly associated with poorer DFS (OR, 4.03; 95% CI, 1.06-15.30; P = 0.040) and abdominopelvic DFS (OR, 5.06; 95% CI, 1.02-25.04; P = 0.047). Inadvertent tumor morcellation during surgery has an adverse impact on the outcomes of patients with early LGESS.