This paper attempted to investigate the effects of integrating Peace Education into Nigeria educational system. Four research questions were designed for the study. The researcher designed an instrument tagged: Questionnaire on effect of Integrating Peace Education (QEIPE). The entire population of two hundred respondents spread across Secondary Schools and lecturers in higher institutions of learning in Ondo State were used as the sample for the study. A 20-item questionnaire structured on a 4-point scale was used for the collection of data. Mean and Standard deviation was used to answer the four research question generated from the study. The findings identified the inclusion of Peace Education in Nigerian School curriculum in order to reduce crime, violence and other social vices in Nigeria. The result of the study further revealed that there is no significant differences between Peace Education and Social Studies. The findings equally identified with the relevance effects of integrating Peace Education in the school curriculum on teachers and students. Based on these findings among others, it was recommended that training and retaining of teachers should be intensified to enable teachers acquire the skills and knowledge to use appropriate techniques and methods to effectively teach Peace Education. Also, while integrating Peace Education concepts, thematic approach in restricting the Social Studies curriculum in social studies and other related subjects should be reviewed in such a way that concepts that are relevant to Peace Education will be reflected and identified.