Recent studies have provided considerable evidence on long-term effects of self-perceptions of aging (SPA) on indicators of successful aging such as health or life satisfaction. To date, little is known about the mechanisms underlying these effects. This study therefore examined whether negative SPA impair the use of self-regulation strategies that include selection, optimization, and compensation (SOC) in case of a serious health event and thus turn into self-fulfilling prophecies for health and life satisfaction. Based on a longitudinal nationwide study with 2 measurement points over a 6-month period in 309 older people (65+ years of age) with multiple illnesses, 2 major findings emerged: First, the occurrence of a serious health event predicted increased use of SOC strategies, which in turn predicted higher self-rated health and life satisfaction. Second, this effect was moderated by negative SPA, that is, in case of a serious health event, the perception that aging is associated with physical losses led to lower use of SOC strategies promoting a healthy lifestyle (B = -0.43, SE = 0.15, p < .01). These findings contribute to a better understanding of the underlying mechanisms of SPA on health by showing that negative SPA as associated with physical losses might impair health-related strategies that are important for maintaining a healthy lifestyle. Future intervention studies could attempt to challenge negative SPA to support effective strategy use in older adults with serious illnesses. (PsycINFO Database Record (c) 2013 APA, all rights reserved).