Inclusion Criteria:

• The patient is a male at least 50 years of age.
• The patient's peak urinary flow rate is at least 4 ml/sec, but not greater than 15 ml/sec, and the voided volume is at least 125 ml.
• Prostate volume must be greater than 30 grams
• The AUA-SI is greater than or equal to 9.
• Patient must be scheduled for a Laser TURP or eligible to be scheduled for Laser TURP
• Patient must be able to complete the study requirements prior to the scheduled laser TURP.
• The patient has signed the informed consent prior to the performance of any study procedures.

Exclusion Criteria:

• The patient has had any prior surgical intervention for BPH.
• The patient is receiving any intervention for prostate disease (either medical or surgical) or is presently enrolled in any study protocol.
• The patient has had a previous hypersensitivity, idiosyncrasy, or clinically suspected drug reaction to dutasteride.
• The patient has taken an alpha-1 blocker within 1 month of randomization.
• The patient has taken finasteride or dutasteride within 3 months of randomization.
• The patient has taken phenylephrine, pseudoephedrine, imipramine, and an anticholinergic or cholinergic medication within 4 weeks of the screening visit.
• The patient has taken an estrogen, androgen, or any drug producing androgen suppression, or anabolic steroids.
• The patient has an inability to urinate.
• The patient has clinically significant renal or hepatic impairment (i.e., creatinine greater than 2.0 mg/dl or AST greater than 1.5 times the upper limit of normal).
• The patient has a PSA level greater than 10 ug/ml (Hybritech).
• The patient requires the daily use of a pad or device for incontinence.
• The patient has had an episode of unstable angina pectoris, a myocardial infarction, transient ischemic attack, or a cerebrovascular accident within the past six months.
• The patient has a penile prosthesis or artificial urinary sphincter.
• The patient has a history or current evidence of carcinoma of the prostate or bladder, pelvic radiation or surgery, urethral stricture, prior surgery for BPH, or bladder neck obstruction.
• The patient has an active urinary tract disease or has undergone cystoscopy or biopsy of the prostate within two weeks prior to the first screening visit.
• The patient has known primary neurologic conditions such as multiple sclerosis or Parkinson's disease or other neurological diseases known to affect bladder function.
• The patient has had documented bacterial prostatitis within the past year.
• The patient has had two documented urinary tract infections of any type in the past year. A urinary tract infection is defined as >100,000 colonies per ml urine from midstream clean catch or catheterized specimen.
• The patient has a severe bleeding disorder that makes laser TURP impossible.
• The patient must be able to stop any anticoagulant, NSAID or anti-platelet for 7 days prior to the laser TURP.
• The patient has had cancer that is not considered cured (except basal cell or squamous cell carcinoma of the skin). A patient is considered cured if there has been no evidence of cancer within five years of randomization.
• The patient has a diagnosis of a thought disorder (i.e., schizophrenia, bipolar disorder)
• The patient has any serious medical condition likely to impede successful completion of the study.
• The patient has a defibrillator that cannot be deactivated during laser TURP treatment.
• A bladder neck to verumontanum distance which is less than 30mm in length as measured by flexible cystoscopy and a total prostate volume <25 ml or >110 ml as measured by prostate volume ellipsoid formula during TRUS.