This study evaluated the influence of street life and gender on aggression and self esteem of children in two metropolitan cities of Anambra State, Nigeria. A total number of 412 participants aged from 13-17 years, comprising of 277(67-2%) males and 135(32.8%) females, with the mean age of 14.91 years and standard deviation of 1.36 took part in the study. They responded to Buss-Perry Aggression Questionnaire (1992), Rosenberg self-Esteem scale (1979), Picture Apperception Test (2012), observation, interview and focused Group Discussion (FGD). The study adopted a 3x2 factorial design to test the hypotheses and used multiple Analyses of variance statistic for data analysis. The results showed that street children differed significantly from non- street children on level of aggression at F (1, 1410) =108.54, p<.05. But did not differ significantly on self-esteem; F(1,410)=1.36,p>.05. Street children who had contact with their families and those who had not, did not differ in level of aggression; F(1,258)=.02,p>.05, and also did not differ in their self esteem status; F(1,258)=.02,p>.05. Male and female street children did not differ in their level of aggression at F (1,258) =0.6, p>.05; but differed in their self esteem status; F (1,258)=4.44,p>.05. The study has provided background empirical information on the emerging cankerworm of street children phenomenon, which will serve as impetus for further studies in this area. Key Words: Street life, Gender, Aggression, Self-esteem, Children.