INTRODUCTION AND OBJECTIVES Nutrition is one of the pillars for proper body development and optimal nutritional status. Anthropometric methods are most commonly used for body composition analysis and are an essential part in the assessment of the nutritional status of individuals and population groups. This study aims to assess the nutritional status of adolescents from Extremadura (Spain); to determine variations in body composition according to the percentiles obtained; and to propose these values as a reference to the nutritional status of the adolescent population in Extremadura. MATERIAL AND METHODS A cross sectional study in the community of Extremadura was performed, including a total of 816 students of Secondary School Education of both sexes; and of all ages in the adolescence stage. The selected secondary schools belonged to populations of different sizes (less than 5,000 to more than 60,000 inhabitants). From the measurements taken, different anthropometric indices were determined and the percentiles 3, 10, 25, 50, 75, 90, 95 and 97 for weight, height and complexion were found. RESULTS AND CONCLUSIONS There were significant gender differences for height, weight, triceps skinfold, arm muscle area and arm fat area. Boys showed greater figures for height, weight and arm muscle area; however, the triceps skinfold and arm fat area was higher in girls. When compared to other national studies, the average height of our population was lower by about 3 cm in both sexes; the average weight was similar, but our adolescents had a higher proportion of fat in the arm. Extremadura girls seem to have a faster growth, reaching final height at an earlier age than the national average, although this height is below average. The boys had a continuous growth in all ages, maintaining national averages.