In a quality school the importance of individual work and competition is reduced while greater emphasis is placed on team work and cooperation. Cooperative learning, team work and cooperation are considered to be the most important principles, crucial for the success in the 21st century (Greene, 1996). Based on these assumptions, the aim of the paper is to examine whether cooperative learning can be confirmed as a significant indicator of a good quality teaching and whether it may positively influence the relationships and processes within a group, in particular among six graders (N = 69) and eight graders (N = 78) in one primary school in Osijek. The results of the research showed that cooperative learning, as an indicator of educational quality, is evident in the school environment, interaction and communication as well as in the students' more efficient relationship towards themselves, the others and the community in general. When it comes to the educational process, the indicators of quality mostly relate to the relationships, readiness to help and cooperate, socializing and peer acceptance as well as one's own responsibility for learning. According to the sudents' responses, cooperative learning is perceived as interesting and useful leading to a relaxed atmosphere whereby the students may overcome their fears of negative evaluation and school failure.