Our aim in this work is to compare the different sociometric classification formulae and to analyze possible connections between each type of formula and each behaviour assessed by peers during adolescence. We classified a total of 1,009 Spanish fourth-grade secondary education students (15-year-olds) using four different systems: two were based on a nomination technique by Coie and Dodge, Newcomb and Bukowski, the third system was a modified version of the latter based on the revision of the neglected status, and a fourth system was based on the qualification scale by Maassen and Laandsheer. Results show a significant relation between all four classifications, but there are also differences among them. The classifications proceeding from the nomination technique share more similarities and also offer a better behavioural characterization of sociometric categories.