Objectives High rates of post-traumatic stress disorder (PTSD) have been observed in earthquake survivors even many years after the event. However, its prevalence among patients with schizophrenia is largely unknown. This study, which was conducted two years after the 2020 Elazığ earthquake, sought to identify risk factors of earthquake-related PTSD for patients with schizophrenia and healthy subjects. Methods Adult patients with schizophrenia ( N = 103) and healthy subjects ( N = 103), who had all survived the earthquake, were recruited from affected areas in the Eastern Anatolian Region of Turkey, Elazığ. A detailed questionnaire of earthquake-related risk factors, Brief Coping Orientation to Problems Experienced (Brief COPE), Multidimensional Scale of Perceived Social Support (MSPSS), and Clinician-Administered PTSD scale for DSM-V (CAPS-5) scales were administered to participants. Results Twelve percent of the patients with schizophrenia and 25% of the healthy subjects had earthquake-related PTSD diagnoses two years after the 2020 Elazığ earthquake. Healthy subjects had a significantly higher rate of earthquake-related PTSD diagnosis when compared with patients with schizophrenia. Religious coping, self-blaming, less emotional support seeking, and going to a safer place on the night of the earthquake were found to be associated with PTSD diagnosis in patients with schizophrenia. History of traumatic events, self-blaming, and less social support from family were found to be associated with a PTSD diagnosis in healthy subjects. Conclusions The earthquake in Turkey created a situation such that significant symptoms of PTSD remained present at two years following the event in both patients diagnosed with schizophrenia and healthy subjects. The patients with schizophrenia have different risk factors for the development of PTSD when compared with healthy subjects. Taking into consideration risk factors, coping strategies, and perceived social support, clinical interventions should be implemented to prevent earthquake-related PTSD.