To assess recent trends of administering adjuvant gemcitabine-docetaxel (GD) chemotherapy for Stage I uterine leiomyosarcoma, and to compare disease-free and overall survival between women who received and did not receive adjuvant GD chemotherapy. All patients diagnosed with Stage I uterine leiomyosarcoma in a California-Colorado population-based health plan inclusive of 2006-2013 were included in a retrospective cohort. Adjuvant GD chemotherapy rates, clinico-pathologic characteristics and survival estimates were assessed. Of 111 women with Stage I uterine leiomyosarcoma, 33 received adjuvant GD (median 4cycles), 77 received no chemotherapy, and 1 patient excluded for non-GD chemotherapy. GD-chemotherapy and no-chemotherapy groups were similar with respect to age, stage (IA/IB), uterine weight, mitotic index, body mass index, and Charlson comorbidity score. Non-Hispanic white women were twice as likely to receive adjuvant chemotherapy as non-white or Hispanic women (37.7 vs. 17.1%, P=0.02). The proportion of women receiving adjuvant GD chemotherapy increased from 6.5% in 2006-2008 to 46.9% in 2009-2013 (P<0.001). There was no significance difference in unadjusted Kaplan-Meyer estimated disease-free (P=0.95) or overall survival (P=0.43) between GD-chemotherapy and no-chemotherapy cohorts. Corresponding adjusted Cox proportional hazard ratios for adjuvant GD chemotherapy compared to no chemotherapy were 1.01 (95% confidence interval [CI] 0.57-1.80, P=0.97) for recurrence and 1.28 (95% CI 0.69-2.36, P-0.48) for mortality. Use of adjuvant GD chemotherapy for Stage I uterine leiomyosarcoma has increased significantly in the last decade, despite unclear benefit. Compared to no chemotherapy, 4-6cycles of adjuvant GD chemotherapy does not appear to alter survival outcomes.