Similar to the Craft Guilds - groups of tradesmen or craftsmen engaged in the same occupation joined together in the Middle ages, since the end of the 18th century associations and commissions of teachers can be traced. They were established in order to improve professional, cultural and social status of the teachers. In the history of education in Slovakia, the Association of teachers in the Malohont region (1786) and The Commission of Teachers from the Liptov region (1836) were the oldest. The first associations had an independent character related mostly to a particular region or church. After the issue of the Hungarian School Law in 1868, there was an increase in foundation of new associations which were formed according to the school types. After the establishment of the independent Czechoslovakia, this increase continued. However, with the arrival of the Communist regime in 1948 a discontinuity can be observed. All the existing associoations were cancelled and replaced by one central trade union (Trade Union of teachers and employees in educational and cultural sector, later renamed to Trade Union of Education and Science). At the upcoming conference, Museum of Education and Pedagogy in Bratislava would like to present the theme of associations of teachers. As a source we use newspapers (periodicals) issued by these associations in the 20th century. The aim of our paper is the classification of the periodicals, analysis of their content, characteristics of the authors and the museum documentation of this part of our collections.