Background: The aim of this study was to describe, explain, and compare the correlations between workload, job satisfaction, and occupational stress levels in Polish midwives working before and during the COVID-19 pandemic. Material and Methods: This study was cross-lagged in nature and conducted in 2 phases at public health facilities. The first phase took place between March and August 2018 before the current pandemic, and the second in February 2021. In total, 133 midwives working before the COVID-19 pandemic and 92 midwives working during the pandemic were surveyed. Results: Analysis revealed that working during the pandemic, personal SARS-CoV-2 infection and workload were positive predictors of occupational stress. Midwives working during the pandemic experienced significantly higher levels of occupational stress compared to the period before the pandemic. Job satisfaction was found to be a negative predictor of stress in both groups, and to mediate the correlation between workload and occupational stress. The positive influence of job satisfaction on coping with stress was stronger in the group working during the pandemic. Conclusions: Workload increased, and job satisfaction decreased, occupational stress levels in both groups of midwives. The COVID-19 pandemic, directly and indirectly, increased midwives’ occupational stress levels, and reinforced the negative correlation between workload and job satisfaction. The results confirm the important role of working conditions in shaping occupational stress levels. Med Pr. 2021;72(6):623–32