Objectives: The purpose of the present study was to investigate, through the lens of conservation of resources theory, the predictive role of 2 positive personality traits in the form of core self-evaluations (CSE) and ego-resiliency (ER) in resource losses and gains triggered by the COVID-19 crisis. Material and Methods: The 2 personality traits, constituting positive person-related resources, were examined in relation to resource losses and gains in both general and distinct life domains: hedonistic and vital, spiritual, family, economic and political, and finally power and prestige. Results: The findings from a nationwide sample of 1000 working adults (65% women; age M±SD 38.93±10.9 years) indicated that CSE negatively predicted resource losses, whereas ER served as a positive predictor of resource gains. The predictive role of personality traits was demonstrated both for resource losses and gains in general and in different life domains. Conclusions: The results of this study highlight in particular the role of CSE as a protective factor of resource losses, and the role of ER as a promotive factor of resource gains, suggesting that both traits might evoke divergent resilience responses when facing prolonged stressful life events. Int J Occup Med Environ Health. 2023;36(4):551–62