Teachers and students often suffer from the same disaster. The prevalence of PTSD in students has been given great attention. However, in acting as mentors to students and their families, teachers are more likely to have vicarious and indirect exposure via hearing stories of their aftermath and witnessing the consequences of traumatic events. There are limited data pertaining to the prevalence of PTSD and its risk factors among teachers. A total of 316 teachers from 21 primary and secondary schools in Baoxing County were administered a project-developed questionnaire which included the items regarding demographic characteristics, earthquake-related experiences, somatic discomforts, emotional reactions, support status, and everyday functioning 2 weeks after the Lushan earthquake, and they finished a 1-to-1 telephone interview for addressing the PTSD criteria of the Mini International Neuropsychiatric Interview (MINI) 3 months after the earthquake. The prevalence of PTSD was 24.4% among teachers. Somatic discomforts (odds ratio [OR] 1.89, 95% confidence interval [CI] 1.06-3.37) were positive risk factors of PTSD. Perceived social support (OR 0.30, 95% CI 0.14-0.62) and being able to calm down (OR 0.25, 95% CI 0.09-0.75) in teaching were negative risk factors. PTSD is commonly seen among teachers after an earthquake, and risk factors of PTSD were identified. These findings may help those providing psychological health programs to find the teachers who are at high risk of PTSD in schools after an earthquake in China.