Aggressive behavior in students is a phenomenon that is often found in schools that has a negative impact. The purpose of this study was to determine:(1) The characteristics of aggressive students, (2) The factors that cause student behavior to become aggressive, (3) The forms of outlet for aggressive student behavior, (4) The consequences caused by students who behaved aggressively, and (5) The perception of people close to students who behaved aggressively. This research uses a case study method with a phenomenological-descriptive approach. The research subject is a 4th-grade elementary school student who behaves aggressively. Data collection in this study uses observation techniques to identify the subject's aggressive behavior, interviews to dig deeper into the problem of aggressive behavior, and documentation to determine the identity and academic achievement of the subject. The data analysis technique used is phenomenologicaldescriptive analysis. Based on the results of the study, it can be concluded: (1) The characteristics of aggressive students include being difficult to manage when angry, often fighting at school, and often cursing, (2) The factors that cause students to become aggressive include biological factors, psychological factors, factors related to social context, frustration factor, (3) Forms of aggressive student behavior include hitting, kicking, harassing friends, (4) The consequences caused by students who behave aggressively include decreased learning achievement, the class becomes noisy, class inventory is damaged, (5) The perception of people close to students who behave aggressively is considered to be naughty students, troublemakers and deserve to be punished.