Swimming is one of the healthiest sports because of its positive effect on all organs and their functions, especially the musculoskeletal, cardiovascular, metabolic, and nervous systems. Meaning it benefits immunity, health in general, and improvement of functional and motoric ability and skills. This is why it's the perfect sport for children of preschool age, it influences all anthropological characteristics in a direct and indirect way. This bachelor's thesis is shortly describing the most important details about swimming in preschool children and methods of work in swimming school including methods of learning, methods of practice, methods of intensity management, methods of safety and prevention, and methods of presentation. For a better understanding of later mentioned influence of swimming on the anthropological characteristics in children of preschool age, there is a short explanation of which age groups are considered when talking about preschool age and an explanation of anthropological characteristics individually. Also, there is mention of a general introduction to physical activity plus a comparison of anthropological characteristics of children in preschool age in different sports like athletics, cycling, tennis, and gymnastics with those who swim. In conclusion, there are summarized reasons why every child should be involved in any kind of physical activity and what kind of benefits swimming has on their body.