Background: There are several techniques to diagnose post-traumatic stress disorder (PTSD) symptoms that correspond to the Diagnostic and Statistical Manual of Mental Disorders (DSM) classification of mental disorders. This study aimed at testing the reliability and construct validity of the Polish version of the PTSD-8. The results obtained in four professional groups of healthcare workers (physicians, nurses, paramedics, other occupations) were compared. Material and Methods: The PTSD-8 questionnaire includes questions on stress reactions manifested by intrusion (4 items), avoidance (2 items), or hypervigilance (2 items). Respondents were asked about their reactions to the traumatic work-related experiences occurring during the COVID-19 pandemic. The nationwide survey conducted in 2022 included 2303 employees, among whom 746 had such an experience and completed the PTSD-8 questionnaire. Results: Based on confirmatory factor analysis (CFA) results, it was shown that a single-factor model is acceptable, but under the condition of modification by correlation of random errors at selected observable variables. The reliability of this scale is very good (McDonald’s Ω = 0.890), and the goodness-of-fit of the overall CFA model is confirmed by: CMIN/DF = 3.969, NFI = 0.982, RFI = 0.964, IFI = 0.986, TLI = 0.983, RMSEA = 0.063. The model estimated for female nurses has the best psychometric properties. In the study group of 2303 respondents, 16.76% met the criteria for PTSD, accounting for 52.74% of those who were traumatized by a work-related event. The PTSD-8 index is M±SD 20.01±5.55 pts (range: 8–32 pts). The PTSD-8 index is significantly higher in women than in men, and higher in nurses compared to other professions. However, the differences between professional groups are significant only for women, and the largest when comparing female physicians and nurses. Conclusions: The analyses confirmed the rationale of further implementation of the PTSD-8 questionnaire in Poland, both as a tool for identifying PTSD and for studying the severity of the syndrome, its determinants and health effects. Med Pr Work Health Saf. 2024;75(1):45–56