For approximately 35 seconds on January 10, 2010, an earthquake measuring 7.0 on the Richter scale struck the small Caribbean nation of Haiti. This research used a preexperimental one-shot posttest to examine the incidence of posttraumatic stress disorder (PTSD) and associated trauma symptomatology from the earthquake experienced by a sample of adult Haitians who were living in temporary shelters located in "tent cities" in Port-au-Prince and a comparative group of displaced individuals who left the capital city and took up residence in the northern rural town of Terrier Rouge. Sixty-five (N-65) participants completed the Impact of Events Scale–Revised (IES-R) to assess the severity of trauma symptomology in the study groups. Data presented are comparisons between the groups on total IES-R scores and the measure subscales for intrusion, avoidance, and hyperarousal. Based on the scores on the measure for the comparison groups 4 months after the earthquake, the findings suggests that all participants in the study exceeded the threshold of an acute stress disorder and most likely experienced PTSD. Implications of using the data in future longitudinal studies on trauma in Haiti are also discussed.