This study addressed the assessment of anthropometric characteristics and body composition of primary school children. The study aimed to determine age and sex related differences in children aged 7 and 8 years, which could be used to assess the health status of children and to monitor the trend of their growth and development. The study included 1520 students (814 second-grade students and 706 third-grade students; 772 boys and 748 girls). The participants were measured for body height and weight, body mass index, body fat percentage, fat mass, and fat-free mass. The results indicated that there were significant differences between boys and girls in body height and weight, fat percentage, body mass index, and fat-free mass (p <.05), whereas there was no difference in fat mass. Apart from the fat percentage, there are significant differences between seven-and eight-year-old children in all other measured variables. The obtained values of anthropometric characteristics and body composition of children are in accordance with the world trends. The differences between the sexes and the generations of children that have been identified are probably due to genetic predisposition, but also to the conditions in which they grow up.