Background: Transurethral resection of the prostate (TURP) is a common surgical procedure for treating benign prostatic hyperplasia (BPH), but it often leads to significant peri-operative blood loss. Dutasteride, a 5-alpha-reductase inhibitor, is typically used to manage BPH symptoms and may also reduce surgical bleeding. This study evaluates the effect of preoperative Dutasteride on peri-operative blood loss during TURP. Methods: This randomized controlled trial included 100 male patients scheduled for TURP. Participants were randomly assigned to receive either Dutasteride 0.5 mg daily for 6 weeks prior to surgery (n=50) or a placebo (n=50). Primary outcomes measured were peri-operative blood loss, assessed through changes in hemoglobin levels and total blood volume collected. Secondary outcomes included the need for blood transfusions, postoperative complications, and recovery times. Results: The Dutasteride group had significantly less blood loss, with a mean hemoglobin decrease of 12.5 ± 1.1 g/dL versus 11.8 ± 1.2 g/dL in the control group (p=0.02). Total blood loss was lower in the Dutasteride group (250 ± 50 mL vs. 320 ± 60 mL, p<0.01), and the need for transfusions was reduced (8% vs. 24%, p=0.03). No significant differences were found in postoperative complications or recovery times.