Optimism is linked to persistence and resilience in adults; however, how optimism might relate to children's evaluations of potentially challenging situations and risk-taking behaviors is unknown. This study examined the role of optimism in 4- to 8-year-old children's (N = 121) perceptions of and willingness to engage in physical activities that ranged from low to high risk. Overall, children perceived activities with more risky elements as more dangerous and were less willing to try them, with this pattern strongest in older children. Moreover, children higher in optimism were (1) more willing to engage in moderate-risk activities relative to children lower in optimism, but (2) less willing to engage in the highest-risk activities--even though they perceived those highest-risk activities as less dangerous than children lower in optimism. These findings support the possibility that optimism motivates children to engage in beneficial moderately challenging activities and protects them from engaging in severe injury-inflicting activities.