The purpose of this study was to examine the relationships among narcissism, self-esteem, and aggressiveness of the juvenile convicts incarcerated in a correctional institution. From the results of the study, we expected to obtain basic information and data needed in developing correctional educational programs to reduce their recidivism. The survey research was done on a population of 189 juvenile offenders incarcerated in a juvenile prison. The study utilized the t-test, correlation analysis and regression analysis as major statistical techniques. The study examined the following research questions: 1. What are the relationships among narcissism, self esteem, and aggressiveness of these juvenile convicts? 2. What are the impacts of narcissism and self esteem on their aggressiveness? According to the findings of correlation analysis, the juvenile convicts' narcissism was found to be significantly associated with their aggressiveness. The findings of regression analysis showed that such variables as the juvenile convicts' narcissism, self-esteem, and the relationships with their parents play a significant role in determining their aggressiveness. The study suggests that we should make more efforts in developing correctional educational program for juvenile convicts, so they can develop a healthy personality.