Background and Objective: Clinical benign prostatic hyperplasia (BPH), a condition that commonly occurs in aging men. It is characterized by the development of lower urinary tract symptoms (LUTS), which can lead to impairment of bladder function and potential renal complications. TURP is the gold standard surgical treatment of BPH. Dutasteride is a 5-reductase and is used for medical management. This study was planned to ascertain the effect of pre-treatment dutasteride in reducing blood loss in patients undergoing transurethral resection of prostate (TURP).Methods: It was a randomized clinical trial carried out at Department of Urology, Jinnah Hospital Lahore in which the total study sample was divided in two groups. One group received dutasteride and the second group was the control group. The study variables were Haemoglobin and Hematocrit values, clotting profile PT and INR, serum Ca levels and uric acid, BMI, prostate volume, residual volume of urine and hospital stay. Results were presented as mean ± SD or frequency (%). The main study outcome variable was mean blood loss (calculated by change in hemoglobin and hematocrit level).Results: 6 (10.3 %) patients needed blood transfusion in dutasteride group and 7 (12 %) in control group (p=0.14). Post-surgery change in haemoglobin and HCT levels were less in dutasteride groups as compared to the control group (ΔHb 1.94±1.27 g/dL vs. 2.16±0.73 g/dL, respectively, p=0.02; ΔHct 5.68 % ± 2.56% vs. 6.52 % ± 2.39 %, respectively, p = 0.04).Conclusion: The present research suggests that administering Dutasteride four weeks prior to the TURPprocedure results in a decrease in blood loss during the peri-operative period, ultimately leading to improved patient outcomes.Key words: Benign Prostatic Hyperplasia (BPH). Transurethral resection of Prostate (TURP), 5 Alpha Reductase Inhibitor (5-ARI)