The study determined relationships between Socio-demographic and PTSD among IDPs in Borno State, Nigeria. Descriptive cross-sectional design of mixed method was adopted for the study. The population of the study comprised all registered IDPs living in 11 IDPs Camps with total of 27212 IDPs. Multistage sampling procedure was adopted to select a sample of 500 respondents using Kieshie formula. Descriptive statistics of frequency counts and percentage were used to describe the demographic information of the respondents while inferential statistics of t-test and One-way ANOVA, Regression and PPMC were used to test the postulated hypothesis at 0.05 alpha level. Questionnaire and PTSD checklist civilian version (PLC) was used as instrument for data collection for the study. The instrument for data collection adopted was validated by five experts in medical psychology and psychiatric Specialist. Pilot study was conducted to establish the reliability of the instrument. The result of the study revealed that: the male and the female IDPs were difference in the prevalence of PTSD in Borno State, hope level will determine severity of PTSD and majority of IDPs have highest hope level in Borno State, Age, Ethnicity, Marital Status and Gender are significant predictors of PTSD among IDPs in Borno State, this shows that 99.9% of the severity of PTDS is not predicted by hope level. The study conclude that, there is significant prevalence of post-traumatic stress disorder among IDPs in Maiduguri, Borno State. The study recommend among others that measures should be put in place by either government or nongovernmental agencies to include mental health intervention in the rehabilitation of victims of insurgency who show one or more symptoms of PTSD.