Until 1989, the reformist current of the National Socialists was one of the backbone elements of the Czech/Czechoslovak party-political system. The political party of the Czech National Socialists was formed in the 1890s and during the years of the First Czechoslovak Republic (1918 – 1938) under the name Czechoslovak National Socialist Party (CSNP) was a regular part of government coalitions. The historiographical description of their activities and their contribution to solving the political, economic, social, and cultural problems of state formation corresponds to this fact. An exception in this context is the history of the party in Slovakia between 1918 and 1938, a period when the party leaders decided to extend the organization's reach to the entire territory of the newly formed state. Apart from partial mentions, we have only a few short historical studies, which are inaccurate in their findings and give only the most basic outline of the Party's policy in this territory. Therefore, the present study is one of the new probes into the Party's activities in Slovakia, aiming to reduce the historiographical debt. Given the limited scope, this article analyses the party's profile in Slovakia intending to evoke its Czechoslovakist programme, the programme of Czechoslovak national and state unity, which was not accepted with understanding in the conservative and especially nationalist and autonomist-oriented Slovak environment or was fundamentally rejected. In the field of political practice, the party projected the concept of unity into the issue of the search for the optimal administrative system of the Czechoslovak Republic. It was opposed not only to the vision of an autonomous Slovakia within Czechoslovakia, which she correctly perceived as the first step in the process leading to the state-law separation of Czechs and Slovaks, but also the provincial system. The ideal, fulfilling the idea of self-government, autonomy, and independence, was the county system. As a probe into the aforementioned topic, this study also analyses the relationship of the National Socialists in Slovakia to Hlinka's Slovak People's Party, which had the most significant electoral support of the population and differed with them programmatically and politically on the issues addressed in our study. It was their primary political opponent.