Of the 2008 Sichuan Earthquake survivors, there was a special group known as Shidu parents, who lost their only child in the disaster. The objective of this study was to estimate the posttraumatic stress disorder (PTSD) prevalence in the Shidu parents from different counties and explore the related risk factors. Across-sectional sample survey was conducted to collect data in 10 heavily damaged counties (n = 176) and 12 moderately damaged counties (n = 148). Probable PTSD prevalence in Shidu parents from the heavily damaged counties (83.5 %) was found to be higher than that in the moderately damaged counties (72.3 %). Many associated PTSD risk factors were identified in the cross-sectional study, such as being of Han ethnicity, losing a young child (18–27), losing a male child, living in the countryside, receiving low social support over the previous 6 years, and having high resilience were significant in the heavily damaged areas, and being of Han ethnicity, having a low monthly income, having a high education level, losing a young child (18–27), losing a male child, and having high resilience in the moderately damaged areas.
