Because increasing numbers of men are seeking treatment for benign prostatic hyperplasia (BPH) from primary care physicians, we sought to assess the efficacy and tolerability of finasteride in a primary care setting. In this randomized, double-masked study, 2112 men with symptomatic BPH received either finasteride (n = 1589) or placebo (n = 523) for 1 year. At 3, 6, 9, and 12 months, urinary symptoms were measured using the American Urological Association Symptom Index (AUASI). Quality of life was assessed using the BPH Impact Index (BII), which assessed bother, worry, physical discomfort, and restriction in activities. Both patients and investigators assessed overall urologic status. Investigators assessed the effect of the drug on plasma lipids in a subset of patients. Patients treated with finasteride had a statistically significant mean decrease in AUASI scores compared with patients treated with placebo beginning at month 6 and continuing throughout the study. At month 12, adjusted mean decreases in AUASI scores were -4.96 for finasteride versus -3.71 for placebo. Statistically significant differences in favor of finasteride were also noted on BLT at months 9 and 12. Patient and investigator overall assessments showed greater improvement in the finasteride group beginning at month 6. The incidence of drug-related sexual adverse experiences was significantly greater in finasteride-treated patients but led to withdrawal in only 2.2% of these patients. Overall Lipid profile was not significantly altered in either group. Based on improvement in symptoms and quality of life, and on its favorable tolerability profile, finasteride should be considered by primary care physicians for management of symptomatic BPH.