Résumé : Purpose: Post-traumatic stress disorder (PTSD) is a frequent psychiatric complication in road accident survivors. However, it remains under-explored and is not taken into account in health policies in Benin. The purpose of this study was to determine the prevalence and risk factors of PTSD after a road traffic accident. This will help to improve its diagnosis and management in Benin hospitals. Materials and Methods: An institution-based cross-sectional study was conducted from November 2020 to January 2021. Consenting victims of road traffic accidents from three hospitals across Benin, aged 18 years and above, living in the south of the country, were administered various questionnaires at 12-month follow-up. Data on PTSD were collected using a pre-tested, structured and standardized post-traumatic stress disorder questionnaire, the PTSD Checklist (specific version) (PCL-S). A logistic regression model was fitted to identify factors associated with PTSD. An adjusted odds ratio (AOR) followed by a 95% confidence interval was calculated to determine the level of significance with a p-value less than 0.05. Results: Out of 865 patients in the cohort eligible for the 12-month follow-up, 734 (85%) participated in the study. The prevalence of PTSD was 26.43% (95% CI: 23.36–29.75). Factors associated with PTSD on multivariate analysis were female gender (adjusted odds ratio (AOR) = 2.14, 95% CI: 1.38–3.33), hospitalization (AOR = 1.87, 95% CI 1.21–2.89), negative impact of the accident on income (AOR = 4.22, 95% CI: 2.16–8.25), and no return to work (AOR = 3.17, 95% CI: 1.99–5.06). Conclusion: The prevalence of PTSD is high in road accident survivors in Benin. The results of this study highlight the need for early diagnosis and a multidisciplinary approach to the management of PTSD patients in Benin’s hospitals.