Objective: Research has consistently highlighted an increased prevalence of mental health problems, such posttraumatic stress disorder (PTSD), depression, and anxiety, following both man-made and natural disasters. Mentalizing and resilience have been previously identified as potential protective factors against the onset of mental health difficulties following such events. Method: This study first identified the prevalence of PTSD symptoms, depression, anxiety, and stress and subsequently assessed mentalizing abilities and resilience as predictors of PTSD symptomatology in a sample of 521 Lebanese participants following the Beirut Port explosion on August 4, 2020. Results: Findings were consistent with existing literature highlighting elevated rates of PTSD, depression, and anxiety subsequent to man-made disasters, with higher rates of mental health symptoms observed among women, those with a preexisting diagnosis of psychiatric disorder (1.5 times more likely to meet the PTSD Checklist for DSM-5 [PCL-5] cutoff score), and those who had to move houses (over 2 times more likely to meet PCL-5 cutoff) as a consequence of the explosion. Higher mentalizing capacities were positively correlated with higher resilience scores and lower indices of mental health difficulties. Each unit increase in resilience scores was associated with a 3% reduction in meeting PCL-5 cutoff, and poorer mentalizing abilities was associated with a 2-fold increase in the risk of meeting PCL-5 cutoff. Conclusions: Presence of a previous psychiatric diagnosis, having to move houses, lower mentalizing capacities, and lower resilience scores were found to predict elevated PCL-5 scores. Findings are discussed within the framework of recommendations for interventions targeting people affected by traumatic events. Clinical Impact StatementFollowing one of the biggest man-made disasters in modern history and in times of peace, this article aims at assessing the mental health consequences of such an event on a sample of the population. We specifically evaluated the prevalence of posttraumatic stress disorder (PTSD), anxiety, stress, and depression and the protective roles of mentalization and resilience. Presence of a previous psychiatric diagnosis and having to move houses as a result of the explosion were found to predict meeting cutoff scores on the PTSD Checklist for DSM-5 for PTSD, and poorer mentalizing was associated with a 2-fold increase in meeting cutoff scores.