Purpose: Aspirin may improve treatment outcomes and increase the survival of patients with prostate cancer, but the results remain controversial. Methods: This study consisted of 483 patients who underwent radical prostatectomy for localized prostate cancer, 231 of whom were in the aspirin group. The associations between aspirin use and freedom from biochemical failure (FFBF), overall survival (OS) and relative factors were evaluated. Results: Multivariate analysis showed that aspirin therapy, T classification, Gleason score (GS), and prostate-specific antigen (PSA) were associated with biochemical failure. The aspirin group had a significantly better FFBF rate (91.1%) at 5 years than the control group (82.3%, p=0.000). Among patients with high-risk disease, the FFBF rate for patients in the aspirin group was 79.1% at 5 years compared to 52.2% in the control group (p=0.000). Conclusions: We demonstrate that the use of aspirin may be beneficial for the biochemical control of prostate cancer. The mechanism of the antineoplastic effect of aspirin is not fully understood. Further clinical trials and large-scale studies will be necessary to confirm the relationship between aspirin use and prostate cancer risk.