The outbreak of the COVID-19 pandemic increased the occupational burden experienced by healthcare workers. The aim of this study was to investigate a change in work satisfaction during the pandemic and specific factors contributing to mental health among healthcare providers. We obtained data from 367 healthcare professionals. Respondents were asked about their satisfaction with selected aspects of work (clarity of procedures, access to personal protective equipment, the flow of information, financial stability and general security) during the epidemic and retrospectively how satisfied they were before the outbreak. They also completed measures assessing mental health: the World Health Organization-Five Well-Being Index, the Patient Health Questionnaire-9, the Generalized Anxiety Disorder-7 scale and the Insomnia Severity Index. The results showed that satisfaction with all safety-related work aspects decreased during the pandemic. The flow of information and financial stability were significant predictors of WHO-5, PHQ-9 and ISI scores. GAD-7 scores were predicted by satisfaction with the clarity of procedures, the flow of information and financial stability. The COVID-19 pandemic significantly changed the lives of everyone. However, due to conditions of employment in Polish healthcare, the COVID-19 pandemic put a great financial strain in addition to pandemic stressors specific to medical staff.