Purpose: To evaluate the impact of baseline characteristics and residual leiomyoma perfusion after uterine artery embolization (UAE) on clinical long-term outcome. Materials and methods: One hundred fifteen patients underwent UAE. All patients were divided into three groups according to achieved infarction rate determined on contrast-enhanced magnetic resonance imaging within 48-72 h after UAE (I: 100%, n = 60; II: 90-99%, n = 32; and III: 0-89%, n = 23). Treatment failure and subsequent re-interventions (surgery, repeat UAE) were assessed for each group and compared using Cox regression analysis (CRA) with respect to the following baseline variables: age, uterine and dominant fibroid volume, number of fibroids, location of largest fibroid, and clinical symptoms. Results: Long-term follow-up was completed after a median of 7.2 years (range 5.1-9.6) with a response rate of 84%. CRA revealed that patients in group III had a 22.2-fold higher risk (p < 0.001) of treatment failure than patients in group I, whereas groups I and II did not differ significantly (p = 0.578). For patients with bleeding-related symptoms only, CRA showed a 5.1-fold higher risk (p = 0.025) of treatment failure than for patients with equally dominant bleeding-and bulk-related symptoms. A 40.5-fold higher likelihood (p < 0.001) of treatment failure was observed for patients in group III with bleeding-related symptoms only compared to those in group I with combined bleeding-and bulk-related symptoms. Conclusion: Incomplete fibroid infarction after UAE is strongly associated with the risk of experiencing treatment failure. Patients with bleeding-related complaints only face the highest likelihood of treatment failure if UAE results in less than 90% fibroid devascularization. (C) 2012 Elsevier Ireland Ltd. All rights reserved.