This study examined personality traits as predictors of delinquent behaviour in adolescents from Lagos metropolis, Nigeria.  The sample comprised two hundred and fifty (250) senior secondary school students, selected through stratified random sampling technique from five secondary schools in Mainland Local Government Area of Lagos State. Four hypotheses were generated for the study and tested using a questionnaire developed by the researcher. Pearson Product Moment Correlation coefficient was used to test hypotheses 1, 2 and 3, while the independent t-test was used to test hypothesis 4. All hypotheses were tested at 5% level of significance. The findings revealed that there is a significant correlation between adolescents’ personality types and manifestation of delinquent behaviours, Also, the study discovered a significant level of association between students’ perception of delinquent behaviours and their personality development, likewise, peer pressure has a significant relationship with manifestation of delinquent behaviours among the students. Finally, the study found a significant gender difference in the extent of delinquent behaviours among students.