Delinquent behaviour among school students is a great concern of governments and educational institutions. Although the authorities and civil society organisations have tried to control the growing trend of school violence, antisocial behaviour among students is significantly increasing. The low delinquency rate among school students in Shah Alam, a city closed to the Malaysian capital, inspired the researchers to explore the association between religiosity and delinquent behaviour. The objective of this study is to explore the relationship between religiosity and the delinquent behaviour of school students. This research employed a mixed method to collect the data. An instrument consisting of 101 questions prepared based on the Muslim Religiosity–Personality Inventory (MRPI) was administrated to measure the level of religiosity. A total of 107 secondary school students (58 boys, 49 girls) aged 13 to 14 years participated in the data collection. A semi-structured interview was used to collect the data from four school counsellors and discipline teachers to examine the relationship between religiosity and delinquency. This research found a moderate level of religiosity among students in Shah Alam while having an inverse relationship between religiosity and delinquency. The researchers, therefore, recommend religiosity as a successful mechanism to control delinquency among school students.