The study determines how aggression or aggressive behavior of Mindanao State University STC-SHS students is related to academic performance in school specifically those who belong to the middle socioeconomic status and those who are Maranaos and visayan speaking. Finds out the following: mestizos - high level Tausugs "low level female " high and with better academic performance male " moderate or low level of aggression and with unsatisfactory academic performance. Sex and ethnicity proved to be significantly related to aggression and academic performance.