By analyzing literary works, correspondence and other materials of the members of the secret political organization in Kyiv "Cyril and Methodius Brotherhood", it became evident that the members were acquainted with the literary and scholarly works of Ján Kollár, Pavol Jozef Šafárik, Václav Hanka and Ľudovít Štúr. Thanks to the use of biographical and, to a lesser extent, bibliographical methods, it was possible to make several clarifications about the familiarity of the members of the Brotherhood with this or that publication, in particular, about one book that V. Hanka sent to M. Hulak. The article clarified a circle of people from whom the members of the organization could get information about Slovak and Czech figures. The considered material constitutes a reliable factual basis for further reconstruction of the echo of the views of Slovak and Czech leaders in the ideology of the Brotherhood. It is proved that Cyril and Methodius members were well aware of J. Kollar's treatise On the literary reciprocity, works of P. Šafárik in Russian translations, etc. There was also active interaction with the literary heritage of J. Kollár and V. Hanka that influenced the work of Mykola Kostomarov.