This study examined the influence of insecurity of school environment on the behavior of secondary school students. A total of 200 students responded to a self-structured validated questionnaire designed for the study. Three hypotheses were formulated to guide the study. Independent samples t-tests were used in analysing the data. The findings revealed that Isiala-Ngwa North and South Local Government Areas were significantly different (p < .001) with regard to the insecurity of their schools, with northern schools having a higher rate of school insecurity. Furthermore, the analysis of data revealed no significant difference (p > .05) between the insecurity of private and public schools although private schools turned out to be slightly more insecure. Finally, no significant difference (p > .05) was found between male and female students’ behaviour due to school environment insecurity. It is recommended that the government should strengthen and motivate its supervisory unit in the ministry of education to enable them carry effective supervision and monitoring of the state secondary schools. Keywords: insecurity, school environment, students’ behaviour, environment