Background: While acute urinary retention (AUR) is a severe complication of benign prostatic hyperplasia (BPH), it can also indicate the progression of this common disease in aging men. This study aimed at exploring the possible relationship between serum interleukin 6 (sIL-6) and AUR in BPH patients. Methods: A cross-sectional study was conducted based on 256 elderly men with BPH in China. The association between the sIL-6 level and the occurrence of AUR was evaluated by univariate and multivariable logistic regressions. The receiver operating characteristic (ROC) curve was utilized to determine the discriminant validity of the sIL-6 level and the optimal cutoff value. Results: The concentration of sIL-6 was significantly elevated in the AUR group (P<0.001). A positive correlation was observed between the sIL-6 level and AUR in BPH patients [odds ratio (OR) =1.365, 95% confidence interval (CI): 1.174-1.586, P<0.001]. Based on the ROC curve analysis for sIL-6, the optimal cutoff point of 4.475 pg/mL was set to identify the occurrence of AUR in these patients [area under the curve (AUC) =0.7596, 95% CI: 0.6976-0.8216, P<0.001]. A high sIL-6 level (≥4.475 pg/mL) had a significantly stronger correlation with AUR (OR =9.666, 95% CI: 4.347-21.491, P<0.001). Conclusions: There was a positive correlation between the sIL-6 level and the occurrence of AUR in elderly Chinese patients with BPH. This study provides potential strategies for the screening of BPH individuals with a possible risk of AUR, which may contribute to the early implementation of effective interventions to improve the quality of life and prognosis. Long-term prospective studies are still required to further illustrate the causal relationship.