Since the beginning of time stress is well common term in all manifestations of human life. Media's are filled with adults who did some reckless things because they were affected by stress. For that reason, it may seem that only adults are under the influence of stress, but even children in primary school have fear of someone / something. The originator of stress research is Hans Selye who defined the stress as a reaction of the organism to various stressors. Dohrenwend and Dohrenwend, who continued his footsteps, say that stress is determined by stressors, and only in the 40s of the 20th century the concept of psychological stress is introduced. It was introduced by Richard Lazarus who in that waybecame the creator of one of the most popular stress theories of today. This theme was chosen for the reason that the concept of stress is known for centuries and is present in all areas of human life, but it is not clearly defined. The aim of my diploma thesis was to get to know the concept of stress and its impact on physical health. Also, to explore what the pupils are afraid of, what causes the stress in their lives and to teach them how to become aware of the fear which causes stress and how to reduce induced stress. The study was conducted on a sample of 14 respondents in one 3rd grade regional school, and the results show that children under school age are stressed because of fear of school.