It is expected that a teacher performs his or her work professionally and efficiently and needs to perfect and develop competences constantly. Lifelong learning is an important factor that shapes the role of a contemporary teacher. The latter has to have well-developed skills of teamwork which can only develop through working in a team. The most important teamwork skills include communication skills, compromising skills, constructive criticism skills and the skill of motivation and giving support. Cooperation among teachers and team teaching are performed in schools on a daily basis, but some school leaders encourage and organize them additionally. Teaching first grade in teams is prescribed by law (Act on Primary School, 1996). Teamwork happens when two or more teachers aim their educational goals at the same group of students in the framework of a specific pedagogical activity. Teamwork comprises three stages: team planning, team teaching and team evaluation. By performing all three stages of teamwork the teachers increase the probability of students’ knowledge improvement. With teamwork we can provide more differentiated forms of work for students, faster feedback information, didactically diverse lessons and an example of interpersonal acceptance and resolution of intellectual conflicts, which allow for higher motivation and better knowledge of the students. At the same time the teachers develop their interpersonal communication skills and increase the ability of perceiving information from different points of view, which they can then critically evaluate and include into their own mind system. The latter includes values, beliefs, ideals, opinions, views and knowledge - all of which change and upgrade constantly. Personal and professional growth of the students as well as the teachers improves the quality of pedagogical work and the school as a whole. All these are the benefits of teamwork which prove that working in a team is efficient, and it has also been proven by different, mostly qualitative researches. The empirical part of this thesis is based on a quantitative research. The data was obtained by a survey including questions and statements concerning the benefits and skills of teamwork. The survey was aimed at the first grade teachers and the preschool educators who work in first grades of primary schools. The goal of the thesis at hand is to determine how often the professionals in first grades perform all three stages of teamwork, how developed their teamwork skills are and which benefits of team work they perceive. I wish to research the connection between the recognized skills and benefits of teamwork and the perception of team efficiency. I was also interested in whether or not there are any differences in the teamwork skills and efficiency perception between the first grade teachers and preschool educators who work in first grades. The correlation between the variables was statistically verified. The aim of the thesis is to become aware of the benefits of efficient teamwork and to understand that teamwork influences many levels of pedagogical work and improve the quality of the school system.