At school, students together learn, study, play, explore and come to new conclusions. By coexisting with other classroom and school students, the opportunity for social development of each individual is indirectly provided. The primary educational role in school is to develop positive relationships between students. With that desirable traits such as tolerance, respect for diversity and understanding are developed. Although, apparently, all children are exposed to equal opportunities for acquiring acquaintance and friendship, the contribution of school to child socialization still depends on many factors. Apart from the fact that the factors are numerous, they are still not enaugh explored. One of the factors that could affect student's popularity, isolation, and choice of friends in the classroom are school grades. This thesis entitled Correlation of primary school pupils’ school marks and social relations in the classroom has goal to determine the sociometric status of students within the sample and to find correlation with school grades. The survey was conducted using a questionnaire that contained questions related to final grades of the last school year and the sociometric test. The survey was conducted on a sample of 6 grades of elementary school of which 57 students were third and 25 fourth grade of primary school. Based on the mentioned goal, 9 hypotheses were set up and it was concluded that the best grades have neglected students, and the worst rejected one. In the subjects of Geography and especially in Mathematics and PSHE was also found a statistically significant correlation between the success and sociometric status of the students. Although there is no correlation between gender and sociometric status of students in general, in the category of popular students, more desirable are boys. It has also been noticed that the success in Mathematics and PSHE differs with consideration of categories of students sociometric status.