Background : Perioperative bleeding and excessive fluid absorption are inherent complications of TURP. These complications are related directly to the size although transurethral prostatectomy is still considered the gold standard for operative treatment of benign prostatic hyperplasia, it is not a procedure without morbidity. the prostate is an androgen dependent organ. This study was aimed to compare the impact of use cyproteron acetate versus dutasteride in reduction of perioperative bleeding in transurethral resection of prostate for treatment of large size prostate. Patient & Methods: This a randomized controlled trial study was conducted for 6 months on 63 patients, from December 2018 to May 2019, who were admitted to urology department in zagazig university patients were randomized through a computer randomization into three equal groups. Results: The current study revealed that Control group was statistically significant decrease of HB and HCT post operative than other two groups and significant less operative time in patients received pre operative medication than control group with consequence decrease need for transfusion as well as less hospital stay .Conclusion: The pre operative use of anti androgen drugs (CPA & dutasteride) in TURP of large size prostate is well tolerated in the properly selected patients and it can help in decreasing the perioperative bleeding and fluid absorption during this surgery also ,operative time ,hospital stay.