Today, we meet more and more aggressive behavior in children of early and preschool age. Aggressiveness can be defined as intentional and unacceptable behavior whose aim is to inflict physical and psychological pain. According to the type, aggressive behavior can be divided into physical, verbal and social aggressiveness. Causes that influence aggressive behavior are divided into biological, social and cognitive determinants. Biological determinants are divided into hormones, temperament and dominance, while social determinants are divided into family relationships, media influence and social interactions in kindergarten and with children in kindergarten. Today, the media are more and more frequent and children's behaviors can turn into unacceptable behaviors. Parents have the greatest influence on age and gender differences in aggressive behavior, because they raise on a different way girls and boys. Prevention is one of the most important aspects of how to prevent a children's unwanted behavior, in this case aggression. The family, the kindergarten and the community participate in this, between which it must be partnership relations in order for prevention, as well as intervention, to be as successful as possible. In addition, educators play have a major role in child's development, and through various programs and environmental arrangements, they influence the child's acquisition of new knowledge and understanding of society, as well as the application and development of their social skills. Also, the game is one of the main ones factors in which the child acquires social skills and develops empathy towards himself and others. The aim of this paper is to describe in more details how to identify aggressive behavior in early and preschool children and how to prevent it in situations where aggressive behavior is observed. Also, the goal is to guide parents on how to act in situations when their child is aggressive and who to turn to for help and cooperation.