Treatment choices for localized prostate cancer appear to vary widely, although it is unclear whether this variation is a result of patient values or other factors. The authors conducted a systematic review of the literature, identifying 70 articles that focused on prostate cancer decision making. Studies suggest that men consider several issues when making treatment decisions. The authors found conflicting evidence regarding the importance that men place on cancer eradication, with considerable variation in how patients interpret evidence regarding treatment efficacy. The number of physicians that men see and the importance of the physician recommendation were found to vary considerably. Although men stated that side effects are important, few patients reported that side effect factors ultimately influenced their treatment choice. To the authors' knowledge, there is little research regarding how patients' personal values shape and influence their decision, or the role of race/ethnicity or socioeconomic status in preferences for treatment. The authors conclude that variations in treatment decisions may be more indicative of differences in the information patients receive rather than truly reflective of underlying patient preferences. Considerable progress is needed in helping patients fully understand how to balance the complex issues surrounding prostate cancer treatment decision making. Cancer 2006. © 2006 American Cancer Society.