The issue of visual recognition of cognates in the Slovenian language will be examined in the thesis. Cognates are words that share a common origin, regardless of whether their meanings have changed over time or remained the same (Chamizo-Domínguez 2008), and are numerous between related languages. Croatian and Slovenian, as the two closest South Slavic languages (Peti-Stantić 2014), share a large number of matching lexical expressions, which is mostly a consequence of their common origin, but also of similar transfer processes during their history. Some of these pairs are completely identical in expression in both languages (e.g. Croatian nagrada and Slovenian nagrada), while some have undergone minor or major expressive changes due to which Croatian speakers often do not recognize the related word in Slovenian (e.g. Croatian vlasnica and Slovenian lastnica). The thesis therefore wants to examine the factors that make easier and difficult the visual recognition of cognates, such as word length, the position of one or more different graphemes, orthographic neighborhood, etc. The first part of the thesis will present the factors that make easier and difficult the recognition of cognates (Jelaska et al. 2021). After that Slovenian-Croatian noun cognates will be analyzed with regard to the degree of expressive concordance (complete concordance, partial concordance and non-concordance) based on data collected from the online corpus of South Slavic languages CLASSLA. The third part of the work will be devoted to experimental research, in which the factors that make it difficult or easier to recognize visually presented Slovenian-Croatian cognates will be tested among the examinees.