The aim of my work was to find out how the time is being used during the PE (Physical Education) lessons at lower secondary schools. I was looking at contents of each part of the lesson, teacher's organizing and controlling activity, the number of pupils who did exercise and thein relation to time effectiveness of exercise unit. The work is dividend into two parts: theoretical and practical. The theoretical part is dealing with a locomotor activity, physical education, physical education in Framework Educational Programme (for Elementary Education), PE teacher, organization and controlling PE class unit and effectivity of schooling the PE. The methods used in a practical part to solve the results were chronometer and observation. The surfy took place at lower secondary schools of four Primary schools in Kadaň. There have been observed fiflen exercise units altogether. KEY WORDS Use of time, exercise unit, physical education, chronometer, exercise time, losstime