This study examines the dynamics of social trust and its interaction with different fears during the COVID-19 pandemic, using a three-wave longitudinal dataset from Sweden (2020-2022). We investigate the stability of social trust across different phases of the pandemic and assess the impact of health, economic, and resource scarcity fears on changes in social trust over time. Our findings suggest that social trust remained relatively stable, supporting theories that view it as an enduring trait. In addition, the study identified significant bidirectional relationships: higher health fears were associated with lower trust in the early stages of the pandemic, while fears of resource scarcity had a more pronounced effect in the later stages. Conversely, individuals with higher levels of social trust were less likely to experience heightened fears, although this protective effect diminished over time. In addition, factors such as education, trust in institutions and satisfaction with government communication positively influenced social trust. These findings highlight the complex interplay between social trust and fear, providing insights into how societies can maintain cohesion during crises and informing policies for effective crisis communication and management.