Prostate cancer treatment decision making requires complex trade-offs among treatment outcomes, and sexual function is a central consideration for most men. Although sexual function is included in prostate cancer decision models, survival and fear of recurrence and cancer progression weigh more heavily in these decisions for many men than concerns about treatment impact on sexuality. In this article, we discuss the importance of sexuality in men's treatment decisions for prostate cancer. We focus on men's preferences for maintaining sexual function and their needs for information about the risk of sexual side effects with prostate cancer treatment. Our review suggests that among men diagnosed with prostate cancer sexual function is less important to men than concerns about survival, but is more highly valued than other side effects and treatment characteristics. However, there is evidence that concerns about sexuality are not in proportion with the associated risk for sexual problems with prostate cancer treatment and men acknowledge unmet needs for information about sexuality in making prostate cancer treatment decisions. Copyright © 2009 by Lippincott Williams & Wilkins.