This study employed correlational design to investigate the relationship between post- traumatic stress disorder and academic performance among secondary school students in Rivers State, Nigeria. Some selected behaviour problems` of aggression, anxiety and depression, caused by post-traumatic stress disorder were studied. Based on the focus of the study, four research objectives, and corresponding research questions and hypotheses were formulated which offers the study a direction. A sample of 327 students identified as traumatized from their responses in the instrument were used for the study. The instrument used was the questionnaire which comprised of thirty (30) items. Data collected from the sampled respondents were analyzed using statistical package for social sciences. All the four null hypothesis which guided this work were tested at 0.05 alpha level. The results obtained showed that negative relationship exists between Aggression and Academic Performances of secondary school students of Rivers state (r = 0.767, p = 0.000). Negative relationship exists between anxiety and academic performances of secondary school students of Rivers state (r = -0.802, p = -0.000), negative relationship exists between Depression and Academic Performances of secondary school students of Rivers State (r = 0.830, p = 0.000). There is no significant difference in academic performance of traumatized male and female secondary school students (t = 0.800, p = 0.424). Based on the outcome of the study, it was recommended that Schools should employ psychologists who should provide psychological interventions that could help take care of symptoms of post traumatic stress disorder such as depression, anxiety and aggression so as to pave way for healthy living and improved academic performance, students who experiences post-traumatic stress disorders should be given cognitive behaviour therapy to enable them to know how their thinking affects their mood and to teach them to think in a less negative way about life and themselves, conducive atmosphere should be provided by government to improve security in schools and enhance teaching and learning, this will go along way in reducing post traumatic stress disorder such as depression, anxiety and aggression, male and female student that experience post-traumatic stress disorder should be given orientation periodically by experts/psychologists for re-educating and re-assurance in life.