Benign prostatic hyperplasia (BPH) is a pathologic disorder that develops in response to the action of dihydrotestosterone on the aging prostate and to changes in stromal and epithelial cells in this exocrine gland. The current therapies for this disorder are chosen after other causes for irritative and obstructive symptoms have been excluded and the status of the urinary tract has been assessed. This evaluation includes a detailed medical history, a thorough genitourinary and neurological examination, assessment of serum prostate specific antigen and creatinine levels, as well as a urinalysis. A urodynamic evaluation consisting of a combined pressure-flow study is required if the diagnosis of obstruction is to be made. Patients with minimal symptoms and normal test results require no therapy. Mild to moderate symptoms can be controlled, at least temporarily, with alpha-adrenergic blockers such as terazosin or doxazosin. A subset of BPH patients with obstructive symptoms respond to the 5 alpha-reductase inhibitor finasteride. Early results with minimally invasive treatments such as laser prostatectomies, hyperthermia, and ultrasonic and radiofrequency ablation appear encouraging for those with moderate symptoms of prostatism. Severe symptoms, urinary retention, gross hematuria, recurrent urinary tract infections, bladder calculi, and hydronephrosis or renal insufficiency warrant transurethral incision, resection, vaporization, or open prostatectomy (for very large neoplasms). Although the morbidities of these latter surgical therapies are not insignificant, these treatments offer the best and most durable results for relief of obstruction and amelioration of symptoms.