PURPOSE: To determine whether the peri-procedural administration of low-dose aspirin increases the risk of bleeding complications for patients undergoing extended prostate biopsies. MATERIALS AND METHODS: From February 2007 to September 2008, 530 men undergoing extended needle biopsies were divided in two groups; those receiving aspirin and those not receiving aspirin. The morbidity of the procedure, with emphasis on hemorrhagic complications, was assessed prospectively using two standardized questionnaires. RESULTS: There were no significant differences between the two groups regarding the mean number of biopsy cores (12.9 ± 1.6 vs. 13.1 ± 1.2 cores, p = 0.09). No major biopsy-related complications were noted. Statistical analysis did not demonstrate significant differences in the rate of hematuria (64.5% vs. 60.6%, p = 0.46), rectal bleeding (33.6% vs. 25.9%, p = 0.09) or hemospermia (90.1% vs. 86.9%, p = 0.45). The mean duration of hematuria and rectal bleeding was significantly greater in the aspirin group compared to the control group (4.45 ± 2.7 vs. 2.4 ± 2.6, p = < 0.001 and 3.3 ± 1.3 vs. 1.9 ± 0.7, p < 0.001). Multivariate logistic regression analysis revealed that only younger patients (mean age 60.1 ± 5.8 years) with a lower body mass index (< 25 kg/m2) receiving aspirin were at a higher risk (odds ratio = 3.46, p = 0.047) for developing hematuria and rectal bleeding after the procedure. CONCLUSIONS: The continuing use of low-dose aspirin in patients undergoing extended prostatic biopsy is a relatively safe option since it does not increase the morbidity of the procedure.