This project is on perception of teachers on the causes of indiscipline among post-primary school students. Indiscipline has become cancer eating deeply in the educational sector. It connotes the violations of school rules and regulations capable of obstructing the smooth and orderly functioning of the school system. Indiscipline has become a social menace which has caused several scholars or educationist unrest and sleepless nights. Therefore, this study investigated the perception of teachers on the causes of indiscipline among post-primary school students. Simple random sampling was used to select one hundred and fifty (150) teachers in Kabba/Bunu Local Government Area of Kogi State. A self-designed questionnaire tagged “causes and consequences of indiscipline questionnaire (CCIQ) were used to gather the required information from the respondents. The instrument has three sections containing items that revealed demographic information, cause of indiscipline and the consequences of indiscipline among post-primary school students. The results revealed that the major causes of indiscipline among post-primary school students are: peer group influence which ranked 1st, poor child upbringing (home) ranked 2nd. Other causes are connected to school factors and societal factors. Six null hypotheses were formulated for the study. The variables considered are religion, sex and length of service. Based on the results of the findings of this study, various recommendations were made on the causes of indiscipline among secondary school students. The major determinants of indiscipline derived i.e. Home, peer group, school, society and media houses should rise up to the responsibility of setting the youths on the right track.