Background/aim: This study aimed to evaluate the role of adjuvant therapy for stage I uterine leiomyosarcoma (LMS). Materials and methods: Clinicopathological data of cases of stage I uterine LMS from 1998 to 2015 were retrieved from the computerized database of Hacettepe University Hospital. The Kaplan-Meier method was used to estimate survival and progression-free survival, and survival differences were analyzed by log-rank test. Cox regression analysis was performed to account for the potential influence of confounding factors. Results: We evaluated the outcomes of 35 patients with histologically proven stage I LMS. The median age at diagnosis was 50 years. All patients underwent surgical treatment and 20 patients (57.1%) received adjuvant therapy. Twelve of these patients (34.3%) received adjuvant chemotherapy, 3 (8.6%) received adjuvant pelvic irradiation, and 5 (14.2%) received adjuvant chemotherapy with pelvic irradiation. The median follow-up duration was 34 months (range: 3-231 months). Twenty-three (65.7%) patients had a recurrence during follow-up. Adjuvant therapy did not significantly improve median progression-free survival or median overall survival. Cox regression analysis did not demonstrate any significant impact of the factors studied, including age, menopausal status, tumor size, mitotic count, staging surgery, or adjuvant therapy. Conclusion: Adjuvant therapy for surgically treated stage I uterine LMS did not improve oncologic outcomes.