As older adults become more susceptible to certain health crises, their preoccupation with their risk of suffering such events increases. Understanding the implications of risk perceptions is critical because they may have consequences for psychological and physical well-being in later life. In the present study of older adults living in the community, the authors examined participants' comparative risk estimates (CREs)--their perceptions of their own risk relative to a similar other's risk--of suffering a hip fracture. Using multiple regression analyses, the authors examined the role of CREs on psychological well-being (negative emotions, life satisfaction) and self-rated physical well-being (general physical health, recent physical health). The authors expected perceived control (PC) to moderate the relationship between CREs and well-being. The predicted interaction did occur: Among individuals with high PC, comparative optimism (perceiving a comparatively low risk) was associated with better psychological well-being (fewer negative emotions and greater life satisfaction) and better physical well-being (general and recent physical health) relative to comparative pessimism (perceiving a comparatively high risk). Among individuals with low PC, there were no differences in well-being between comparative optimists and comparative pessimists. These findings suggest that the protective effect of comparative optimism on well-being is limited to older adults who have a strong sense of control.