INTRODUCTION: Physical efficiency determines ability to undertake various every-day activities. The greater it is, the better a person’s quality of life and health becomes. AIM: The aim of the study was the characterization of motor skills in primary school students from the 7th and 8th classes, and to compare individuals training volleyball with those participating only in physical education classes. MATERIAL AND METHOD: The research material included 76 individuals, 41 of whom were from the training group and 35 from ordinary classes of the 7th and 8th classes of primary school. The method was the Physical Efficiency Index created by Zuchora, by means of which speed, jumping ability, arm strength, abdominal muscle strength, flexibility and stamina were evaluated. In addition, the students’ parents completed the author’s questionnaire about their own and their children’s physical activity and eating habits. RESULTS AND CONCLUSIONS: The training group obtained 21 points on average and the group that did not train volleyball – 17. Despite this difference, both classes qualified for an average good mark – in the volleyball classes, over 50% got good or very good marks, whereas in the ordinary classes, more than 50% received good or satisfactory marks. In the individual trials, statistically significant (α⩾0.05) differences were found in the jumping ability, arm strength and stamina. Students of sports classes demonstrate better physical efficiency and the biggest differences are visible in the area of stamina. Regular physical activity has a positive impact on the students’ efficiency and fitness