OBJECTIVES To identify predictive parameters of different treatment outcomes after prostatic artery embolization (PAE) in the treatment of lower urinary tract symptoms secondary to benign prostatic hyperplasia. PATIENTS AND METHODS A post-hoc analysis of data derived from the 48 patients undergoing PAE in a randomized, open label, non-inferiority trial was performed. Relative changes in the International Prostate Symptoms Score (IPSS), absolute changes in maximum flow rate, and relative changes in MRI-assessed prostate volume from baseline to 12 weeks were defined as the outcomes measures of interest. Their association with various baseline characteristics and measures, technical details of PAE, and early postoperative measures was analyzed using Spearman rank correlations and Wilcoxon rank-sum tests. The most promising predictors were further evaluated in ROC analyses. RESULTS Higher total prostate and central gland (i.e., central plus transitional zone) volumes were associated with more pronounced improvements in the IPSS (Spearman rank correlation (rs): -0.35 and -0.34; p = 0.01 and p = 0.02 respectively) and the maximum flow rate (rs: 0.31 and 0.39; p = 0.05 and p = 0.01, respectively). ROC analyses suggested that volumes of 39 and 38 mL for total prostate and central gland volume, respectively, would be optimal cutoff points to predict PAE success as measured by the IPSS. Other anatomical characteristics of the prostate such as the central gland index also showed an even more distinct correlation to the improvement in maximum flow rate (rs: 0.46, p = 0.003). The relative changes in prostate volume were clearly dependent on the technical performance of PAE. Occurrence of postoperative pain and blood levels of prostate-specific antigen (PSA) and C-reactive protein (CRP) emerged as potential early stage outcome predictors after PAE. CONCLUSION Baseline and perioperative findings might help to guide patient selection and outcome prediction for PAE. Patients with larger prostates have a higher chance of success with PAE. Larger scale clinical trials including a longer follow-up are warranted to further elucidate the most suitable patients for PAE. This article is protected by copyright. All rights reserved.