<jats:sec><jats:title>Background</jats:title><jats:p> Tris-acryl gelatin microspheres (TAGM) and gelatin sponge particles (GS) have been used in uterine artery embolization (UAE) for leiomyoma. No direct comparisons of both embolic agents have been reported. </jats:p></jats:sec><jats:sec><jats:title>Purpose</jats:title><jats:p> To compare the outcomes of UAE with TAGM with those of UAE with GS for uterine leiomyoma. </jats:p></jats:sec><jats:sec><jats:title>Material and Methods</jats:title><jats:p> This was a non-randomized, single-institute, non-inferiority study. Between July 2008 and August 2015, 67 consecutive patients with symptomatic leiomyoma underwent UAE. GS was used for the first 49 patients and TAGM was used for the following 18 patients. The primary endpoint was tumor infarction on contrast-enhanced magnetic resonance imaging (MRI) 1 week after UAE. The secondary endpoints were changes in symptoms and quality-of-life scores with UFS-QOL questionnaires at 4 months, and adverse events (AEs) in the 4 months after UAE. </jats:p></jats:sec><jats:sec><jats:title>Results</jats:title><jats:p> The baseline characteristics of both groups were similar. Complete or nearly complete tumor infarction (≥90%) was achieved in 94.4% (17/18) of the TAGM group and 93.6% (44/47) of the GS group. This difference (0.8%; 95% CI, –11.9% to 13.5%) indicated the non-inferiority of the TAGM group to the GS group, with a pre-specified non-inferiority margin of 20%. No significant differences were observed in improvements in symptoms or quality-of-life scores at 4 months ( P = 0.56 and P = 0.19) or in 4-month AEs ( P = 0.29). </jats:p></jats:sec><jats:sec><jats:title>Conclusion</jats:title><jats:p> The outcomes of UAE with TAGM were comparable to those of UAE with GS, suggesting that both embolic agents are acceptable for the treatment of leiomyoma. </jats:p></jats:sec>