This study aimed at investigating the promotion of peace education for behavioural changes in public secondary schools in Calabar Municipal Council Area of Cross River State. A descriptive survey design was adopted for the study. A set of questionnaire items were validated and used for the collection of data involving 310 respondents, selected from a total population of 773 teachers and 10 principals representing 39.5% of the total population of 783. The questionnaire was titled: Promoting Peace Education For Behavioural Changes In Secondary Schools Questionnaire (PPEFBCISSQ). The reliability of the instrument was determined by using the split-half method which involved 31 teachers outside the study sample. Pearson product moment correlation coefficient was used to analyze the data. The reliability estimate was between r = 0.60 and r = 0.70. The result of the analysis showed a positive significant relationship between promotion of peace education and behavioural changes in curbing violence fighting, aggressiveness and conflict among students when tested at p < 0.05 level of significance. It was therefore recommended that Teachers who implementers of the National policy on Education and school curriculum through civic education should promote peace education by inculcating in students good value system, that can aid the curbing of aggressiveness, fighting violence and conflicts in school system.