A cross-sectional descriptive study on the prevalence and correlates of posttraumatic stress disorder (PTSD) following the 2010 Jos crisis was carried out among medical students in the University of Jos. The aims of the study were:  To determine the pattern and prevalence of exposure to traumatic events among medical students in the University of Jos.  To determine the prevalence of PTSD among medical students in the University of Jos.  To determine the socio-demographic correlates of PTSD among medical students in the University of Jos. The study population were medical students from year two to year six with a total population of 836 (513 males and 323 females). A proportional sample of 200 students comprising 123 males and 77 females was drawn. None of the participants declined consent. A two staged interview was conducted and lasted twelve weeks with each participant completing the socio-demographic, Impact of Event Scale and Posttraumatic Stress Disorder Checklist-Civilian version (PCL-C) questionnaires. Those with PCL-C scores of 21 and above proceeded to the second stage with the administration of the Composite International Diagnostic Interview (CIDI) - PTSD module. The data was analysed using the Epi-info, version 3.4.1. The mean ages were 24.22±2.73 for males and 22.73±2.08 for females with a total mean age of 23.64±2.59. Only 4(2%) of the participants were married. More than half (50.5%) resided in Jos town at the time of the study. Exposure to traumatic events prior to the index case was quite common. Majority of the students, 144(72%) were previously traumatized with death of family members or close friends (13.9%), community violence (9.7%) and physical abuse and assault (6.3%) being the top three traumatic events experienced prior to the index trauma. A good number of the participants experienced more than one traumatic event prior to the index trauma. The leading combinations of previous traumatic events were death of family members or close friends/ community violence (9.7%), motor vehicle accident/ death of family members or close friends (3.5%) and witnessing of domestic abuse/ death of family members or close friends (2.8%). More than two-thirds, 124(86%) of those with previous history of trauma scored 21 and above on PCL-C signifying the likelihood of having a diagnosis of PTSD. These were subjected to clinical interview using PTSD module of CIDI. A high prevalence rate (23.5%) for current PTSD was found. This comprised 30.6% of the subjects with previous history of trauma and 30.3% of the participants that scored above 21 on the PCL-C. Most of the participants endorsed the 2010 Jos crisis as their worst traumatic experience ever. Individual situational experiences during the event correlated strongly to their psychological symptoms. Previous history of trauma (p=0.005), loss of personal possession with associated threat to their lives (p=0.001) and witnessing death of relatives or friends (p=0.012) during the crisis were significantly associated with having a diagnosis of PTSD. Personal scores on Impact of Event Scale were also significantly associated with a diagnosis of PTSD in the study (p=0.001). The odd of having PTSD was five times (OR=5.3) higher among those who were previously traumatized. Age, gender, marital status and social support were not significantly associated with PTSD in the study. The high rate of PTSD among the students as a result of 2010 Jos crisis and more than half of the participants being previously traumatized calls for serious concern because of its ability to modify the psychological response to subsequent trauma. Similar studies and early psychological intervention to trauma victims are advocated as they can improve the educational and occupational prospects of students, enhance their quality of life and reduce the risk of psychiatric morbidity.