This article studies the presence, resilience, and direction of the self-positivity bias under various conditions to examine the role of self-esteem maintenance as an important antecedent for the bias. Experiment 1 manipulates the perceptions of the uncontrollability of cancer and presence of base-rate information as independent variables that together eliminate the self-positivity bias in perceptions of the risk of cancer. Experiment 2 shows the same effects using 4 life events that differ in terms of valence and perceived controllability; that is, base-rate information affects self-estimates for uncontrollable life events, reducing the self-positivity bias, but does not affect self-estimates for controllable events. Experiment 3 shows that these effects only apply to optimistic individuals who fail to incorporate base-rate information into their self-perceptions for controllable events. In contrast, pessimists use base rates to update their self-estimates irrespective of the controllability of the event. Overall, the pattern suggests that self-positivity is attenuated in conditions that implicate self-esteem. Implications for health care marketing are discussed.