On the 23 January 1923, The Marijampolė County Education Commission decided to establish a primary school in Kazlų Rūda. The railway board provided two rooms, one was used by the students of sections I, II and III, and the head of the primary school, Kazimieras Bukšnys, lived in the other. The ground floor housed the post office. Later, as the number of students grew, families were moved out of the premises and the entire upper floor was turned into the school. On the 1 February 1923, at the initiative of A. Baub, the chairman of the parent committee of Kazlų Rūda’s elementary school, the railway board gave the building to the education department of Marijampolė county. At the beginning, the school’s inventory was very poor, there was a lack of school benches, 4-6 students were sitting in three-seater and four-seater benches. Parents of students contributed by ordering and buying some part of inventory from Kybartai and making the other part themselves in the auxiliary building of the railway station. This building was handed over to the school, and it housed a wood and metal workshop equipped with the simplest machine tools.