The study investigated the effect of behavioural counselling on deviant behaviours among junior secondary school students. The descriptive survey research design was adopted for the study. Two research purposes, two research questions guided the study. A pretest and posttest study where carried outside the study area at two weeks interval. The population comprises 118 school counselors randomly drawn through stratified random techniques, were used for the study. A self-made attitude questionnaire titled “effects of behavioural counselling on deviant behaviours among junior secondary school students (EBCDBJSSSQ) made up of 25 items were used for data collection. The study had a reliable coefficient of 0.78 determined through Pearson Product Moment mean and standard deviation in answering the research questions. The findings show that behavioural counselling techniques are effective in curbing deviant behaviours among junior secondary school students. The study concludes that there are different types of deviant bhaviours exhibited among junior secondary school students. The study then recommends that every secondary school heads should allow school counsellors to organize orientation service programmes for the new students where the school rules and regulations be spelt out to them on admission.