Physical activity is very important for the growth and development of children, as well as for socio-emotional development. Socio-emotional development is one of the most important developmental tasks in a child's life. It refers to successfully recognizing and dealing with one’s own and others ’emotions in a social context. The socio-emotional development of a child is influenced by numerous factors during his or her growing up such as the family situation, socioeconomic status, nutrition, the environment in which he or she lives and many others. The assumption is that physical activity, due to the many benefits it has on the human body, can also have a positive effect on socio-emotional developement. The aim of this paper was to show the results of research that prove the positive impact of physical activity on the socio-emotional development of children. Research covered in this paper has shown that physical activity can help the proper socio emotional development of a child due to the numerous positive actions on human physical and mental health. By including a child into a sport or other physical activity, it may improve his emotional state, reduce anxiety feelings, strengthen self confidence, and help establish socialization. Children who are physically active find it easier to make social contacts and have more developed forms of prosocial behavior, such as compassion, the desire to help others, the willingness to work together, feelings of responsibility for the team and fitting into the group. Many research which connect socio-emotional development with physical activity place emphasis on social variables, especially the impact of parents or other significant adults in a child’s life. Experts argue that parents or guardians should be an example to their children in participation in physical activities, or better yet, attend physical activities with children. Also, the school as a educational institution should provide children with all possible conditions to achieve the development of socio-emotional competencies through physical activity.