Earthquakes are one of the most studied uncontrollable natural conditions that cause negative psychological consequences. Although health-care workers (HCWs) are trained to manage trauma in the out-of-hospital area, uncontrollable tragic events in the earthquake field and exposure to life-threatening situations may cause psychological disorders. This study aimed to investigate the risk of the development of probable posttraumatic stress disorder (PTSD) and the factors affecting it in HCWs working in the region during major earthquakes centered in Kahramanmaras. The questionnaire, which consists of the Turkish version of the 20-item PTSD Checklist for DSM-5 (PCL-5) self-report measure assessing DSM-5 symptoms of PTSD, was applied to HCWs. The Turkish version of the PCL-5 proved validity and reliability, with a cutoff point of ≥47 to diagnose probable PTSD. In this study, of the 79 HCWs, 62.7% were male. The overall probable PTSD rate was 37.9% (n = 30). Female participants had a significantly higher probable PTSD rate than males (P < 0.001). The nurses met probable PTSD criteria statistically significantly more than the doctors (P = 0.026). The multiple regression analysis for predictors of probable PTSD revealed that female gender, previously working in a level 1 hospital, and being a nurse were among the independent risk factors. This study showed that the probable PTSD rate was high among HCWs and that female HCWs were at higher risk for PTSD. HCWs, especially females working in the disaster area, should be closely monitored, and more mental health services should be provided to ensure that HCWs receive the necessary support in the postdisaster period.