Benign prostatic hyperplasia (BPH) is common among aging men. Untreated BPH may lead to complications including urinary tract infection, acute urinary retention, and obstructive nephropathy. Diagnosing BPH can be challenging because lower urinary tract symptoms are found in conditions other than BPH, and prostate size correlates poorly with symptoms of obstruction. Nonetheless, a careful medical history and physical examination, along with prudent use of diagnostic tests, can yield an accurate diagnosis. We review the evaluation of men with suspected BPH and indications for referral to a urologist for invasive therapy. We also review supporting evidence and treatment considerations for saw palmetto and the 2 major classes of prescription medications, alpha1-adrenergic antagonists and 5alpha-reductase inhibitors.