The assessment of body size and composition is common in estimating relative body fat in footballers. The purpose of this study is to determinate the body size and body composition in soccer players who play in the first league club of Perú. In addition, this study specifies possible differences in the monitored characteristics related to the position each player has in the game. Skinfold and body composition sizes were measured in 68 elite soccer players. The average values were compared between four specific positions in the game (goalkeepers, defenders, midfielders, and attackers). The results indicate that there were no significant differences between playing positions in the variables of body weight, height, age, professional experience, body-fat percentage, and fat mass (P>0.05). However midfielders showed lower values of fat-free mass in relation to other playing positions, and they are lower and lighter with regard to the goalkeepers (P<0,001). We conclude that the size and body composition are important when analyzing soccer players according to their position, despite the appearance of only minor differences between them.