The aim of this paper was to identify risk and protective factors associated with the development of physically aggressive behavior in the population of preschool and younger elementary school children. The theoretical part of the paper gives an overview of the various changes in the perspective of childhood and society's attitude towards children throughout history, and overview of the developmental characteristics of preschool and elementary school children. The paper used the definition of aggressive behaviour as the behaviour with intention of causing or attempting to cause harm to oneself, other persons or objects. The relationship between violence and aggression is shown, whereby aggression does not exclude physical forms of violence, but mostly refers to less extreme intentional behaviours that can cause negative psychological and/or physical consequences for victim and the perpetrator. The main theories of aggressiveness are presented, which mainly explain the development of aggressive behavior by the action of biological or social factors. The paper presents and uses Bronfenbrenner's bioecological model of human development, which explains physically aggressive behavior as a result of the interaction between a person's innate, individual characteristics and the characteristics of his social environment. According to their effect, these characteristics are divided into risk and protective factors, and their effect on the child is described in the last chapter of the theoretical part of the paper. The empirical part of the work analysed data collected from a sample of 393 parents who participated in the survey and 378 children who participated in interviews with educational specialists. Three kindergartens and three elementary schools from the area of Slavonia participated in the research. The results revealed significant differences in the frequency of physically aggressive behavior of children with regard to their sex and age, the number of brothers or sisters, the number of household members and the working status of the mother. A significant correlation between the frequency of physically aggressive behavior of children with parenting style, sociometric status in the educational group or class, propensity for violent media content and satisfaction with the parents' work environment was established. The significant predictors of physically aggressive behavior were age, attachment to parents, acceptance among peers and parents' satisfaction with the work environment. The paper contributes to the understanding of the factors related to the physically aggressive behavior of children and indicates the importance of measures to prevent this behavior, which, in addition to the child, must also include other environments with which the child communicates, such as family, peers, educational institutions and the media.