BackgroundPost-traumatic stress disorder is the most common mental disorder occurring among survivors of road traffic accidents. However, it remains under-explored and is not taken into account in the health policies of Ethiopia. Therefore, this study aimed to identify determinant factors of post-traumatic stress disorder among survivors of road traffic accident patients in Dessie Comprehensive Specialized Hospital, North-East Ethiopia.MethodsA facility-based unmatched case–control study design was employed from February 15 to April 25, 2021, in Dessie Comprehensive Specialized Hospital, with a total sample size of 139 cases and 280 controls selected by using a simple random sampling technique. Data were collected by pretested, interview with a structured questionnaire. The data were entered using Epi-Info, then exported and analyzed using STATA. The bi-variable and multivariable binary logistic regression model was used to identify determinant factors of post-traumatic stress disorder among survivors of road traffic accident. Adjusted odds ratio with a 95% confidence level was used as a measure of association. Variables with a p-value less than 0.05 were considered as statistically significant.ResultA total of 135 cases and 270 controls participated in this study, with a response rate of 97% and 96%, respectively. In the final multivariable analysis, being male [AOR = 0.43, 95% CI: 0.32–0.99], primary educational status [AOR = 3.4, 95% CI: 1.04–11], presence of personal psychiatric history [AOR = 2.12, 95% CI: 1.17–3.92], presence of fracture [AOR = 2.41, 95% CI: 1.2–4.8], witness of death [AOR = 2.25, 95% CI: 1.26–4.30], presence of comorbidity [AOR = 2.29, 95% CI: 1.28–4], good social support [AOR = 0.71, 95% CI: 0.12–0.68] were significantly associated with post-traumatic stress disorder among survivors of road traffic accident patients.ConclusionPTSD following road traffic accidents is common. A multi-disciplinary approach was therefore essential in the management of road traffic accident survivors at the orthopedic and trauma clinics. Patients with poor social support, bone fracture, witnessed death, comorbidity, and females should be routinely screened for post-traumatic stress disorder in all road traffic accident survivors.