The current study named “A study of gender differences in the expression of Relational aggression in adolescents” was carried out in Delhi, India. Aims of the study were to measure and compare expression of relational aggression between adolescent boys and girls. 92 adolescents (54 boys, 38 girls; mean age-13 years) participated in the study and fulfilled the relational aggression questionnaire. Results of the study showed that 34% of the adolescents were found to have high level of relational aggression. Boys and girls did not differ significantly in their expression of relational aggression.