OBJECTIVE To describe treatments for localized prostate cancer: surgery, external radiation therapy, and brachytherapy; watchful waiting might also be appropriate. Patients trying to decide about treatment ask family physicians for advice. This article sets out a framework to aid patients (and physicians) in the, decision. QUALITY OF EVIDENCE Only two randomized studies composing of different treatments were identified. Because of the paucity of level I or II evidence, suggestions in this review are largely based on I expert opinion and consensus statements. MAIN MESSAGE Risk-grouping and nomograms are useful for assessing treatments and estimating outcomes of treatment. Where treatments are, equivalent, decisions can be based on perception of toxicity and convenience. Effects on patients' lives and on sexual, urinary, and bowel function vary by treatment modality. CONCLUSION Men with low-risk prostate cancer should decide on treatment based on their perception of how treatment will affect their lives. Men with higher-risk cancers might accept adverse effects on their quality of life in return for longer survival.