In the article the author discusses the circumstances which condition the phenomenon of youth aggression. The first part of the paper presents the theoretical issues related to the topic, e.g. definitions of aggression, its typology, theories of aggressive behaviour, factors behind aggression as well as issues related to preventing aggression. The second part of the article presents the data from a study into the causes of aggression within the family, the data from a study of personality aspects in the context of aggression and the data from a study of the relationship between aggression and interaction with others, including the position in the peer group. The paper also presents study results concerning the causes of aggression and violence in school perceived by youth and the solutions suggested by young people. A thorough study of the circumstances which condition aggression has the potential of contributing to counteracting such behavioral problems and to preventing them. Young people, perceived by others and themselves as aggressive, in fact need help, whereas their aggression is an attempt to cry out for help from the outside.