To measure the level of aggression amongst school-going adolescents at various private schools in Lalazar, Rawalpindi. A cross-sectional study was conducted in eight private schools in Lalazar, Rawalpindi from January 2019 till October 2019 recruiting 400 students aged 10-19 years through convenience sampling technique. Data was collected through face-to-face interview using a validated tool called BPAQ, and analyzed using SPSS 21. Out of 400 students 236(59%) were males and 164(41%) females, with mean age of 14.59 + 2.36 years. Overall, 62.87% of respondents had aggression with a mean value of 90.4525+17.034, which falls under high level of aggression The mean value for physical aggression was 26.9525 + 6.17, for verbal aggression was 15.420 + 3.62, for anger was 23.707+ 5.405, and for hostility was 24.3725 + 5.346. The means were higher for females in all domains except hostility No statistically significant gender-based difference was found in aggression levels. (p<0.05). Majority of school-going adolescents in the study showed increased levels of aggression in all its sub-dimensions, that include verbal, physical, hostility and anger. The means were predominantly higher in females.