This study aims to evaluate the impact of COVID-19 coronavirus on employees’ psychological well-being; to explore whether socio-demographic characteristics of employees predict the negative effect of the pandemic on their well-being; to analyze factors (level of trust in the official and informal sources of information, expectations and concerns, coping activities and emotional states) associated with such negative effect. A total of 1.937 completed online surveys were gathered from May 11–June 7, 2020. After excluding participants whose psychological well-being subjectively was not affected by COVID-19 outbreak, the overall sample was divided into high (374 employees) and low-affected (762 employees) groups. Statistically significant differences between emotional states, concerns and coping activities of participants from high- and low-affected groups were found. The high intensity of the COVID-19 outbreak’s influence on employees’ psychological well-being has positive correlations with respondents’ financial circumstances, negative emotional states (tension, stress, anxiety, and depression symptoms), concerns and expectations regarding work, financial complications, health, and social issues. It also positively correlates with such coping activities as seeking support from a professional psychotherapist or psychologist.