As a child grows and develops, he or she spends more and more time in relationships outside the family, so peer socializing within their classrooms occupies an important place in everyday student activities. The aim of this thesis was to check the notion of popularity and friendship and to determine the relationship between sociometric status, self-assessment of popularity, social integration, school satisfaction and school success of students within classrooms. Three fourth grade classes of elementary school participated in this study. The assumptions have been partially confirmed. The results did not confirm an association between self-assessment measures and sociometric status. A positive association was confirmed between student selection for learning and sitting together with student school achievement. The results of the overall sociometric status showed that 14% of the sample consists of popular students, selected more than ten times and that those isolated are about 6%, unselected. Research has confirmed that students at this age choose same-sex friends, meaning that girls choose girls and boys choose boys for different activities. The results show that students do not yet differentiate the value of an individual person for a particular activity, because 35% of them chose the same person for all three criteria in the first choice, and 61% of them chose the same person for two criteria, while only 4% of students chose different persons for each sociometric criterion. In the descriptions of the characteristics of a popular student and a good friend, it was found that students recognize some of the six fundamental virtues in friends, while the perception of popularity is divided into positive and negative traits.