The aim of this study is to identify relevant correspondence, similarities and differences in the pronominal system of the Bosnian/Bosniak, Croatian and Serbian language (abbreviated BKS; B, K, S or B, K and S), which until the beginning of 90s of the 20th century constituted a common Serbo-Croatian or Croato-Serbian language.After the part which is devoted to general aspects of the pronouns of researched languages, it is continued with the analysis of this lexical category on the Slavic-diachronic and synchronic level (see ?retrocorrelational? ? a system of relations created during the development of language), after which is proceeded with the description of pronominal system in BKS within ?intracorrelational? (the system of relations within each language separately) and ?intercorrelational? (the system of relations between very similar languages with the same dialectal elements ? ?tokavian). The interpretation of the intracorrelational relates to dialectal aspects of the given language, while the analysis of intercorrelational is performed by using Gralis BKS-Korpus (abbr. Gralis-Korpus) ? parallel corpus for the research of Bosnian/Bosniak, Croatian and Serbian language developed within the FWF-Project ?Differences between Bosnian/Bosniak, Croatian and Serbian language? (2006?2010). Additionally, it is used Gralis-MorphoGenerator ? a program for automatic morphosyntactic annotation (marking), production of frequency lists, generation of morphological forms and paradigms, searching of grammatical forms in Gralis-Korpus, and also for mastering the grammatical system in the process of education.The dissertation is thematically divided according to the individual functional pronominal categories, in which are discussed and described characteristic, specific and identifiable units of each subspecies.