The topic of this paper is a discussion as a communication skill at an early school age. The theoretical part of this graduate thesis will define the term of discussion as a component of language expression in teaching of Croatian language and as a part of oral language expression. This paper highlights the purpose of discussion in the role of oral task in teaching of Croatian language. It refers to development of communication skills of a pupil and increase of communication competences in Croatian language in teaching of the same subject and in everyday life. The practical part of the thesis is based on the analysis of textbooks for the third and fourth grade, published by Školska knjiga. The purpose of the textbook analysis is to check the representation of discussion as single teaching unit of language expression and representation of discussion among methodical instruments of mentioned textbooks.. Analysis of representation of discussion among methodical instruments will cover three sets of textbooks and workbooks for the third and fourth grade of primary school, published by Školska knjiga. Except the textbook analysis, the practical part of this thesis describes two teaching lessons: oral task of discussion on the topic of U laži su kratke noge in the third grade of primary school and oral task of discussion on topic of Postao/postala sam čovjek/čovjekica in the fourth grade of primary school. The goal of performed lessons is to motivate pupils to take part in the discussion respecting courtesy rules, to stick to the topic of discussion, to respect opinions of others, to express their own opinion and to check how pupils accept discussion as oral task.