This MA thesis is based on sociolinguistic research intended for establishing the way in which Istrian high school students perceive different varieties of Croatian language spoken in Istria and Croatia, and the geographical space they would assign to these. As a theoretical framework we used perceptual dialectology, a subdiscipline of sociolinguistics and a part of folk linguistics that uses draw-a-map as its fundamental method of data collection. Students filled out sociolinguistic questionnaires that consisted of blank maps of the Republic of Croatia and the Istrian County, and participants also answered some open-ended questions. The thesis is aimed at studying a conventionalized link between language varieties and mental maps of the participants, whilst taking into consideration various factors related to the connection between language and regional identity in Istria, to evaluation of the varieties the participants have marked taking into account correctness, social attractiveness and intellectual capacity of their speakers (i.e. overt and covert prestige), to language ideologies, but also to the dialectal diversity itself, as well as to the sociolinguistic situation in Croatia, which constitutes the macro level of the research. We also paid attention to naming practices, that is, the glottonyms the participants used. General tendencies in the way of mapping in this kind of research have been confirmed: the participants most frequently mapped marked and local varieties, they established more diversity around their place of residence than in more remote areas, and the variety they evaluated as the least intelligible was, at the same time, the least socially attractive, correct, or prestigious. Moreover, we established that semiotic processes of erasure, iconization (especially of phonetical features) and fractal recursivity participate in the process of forming such ideas. For Istrian high school students, the most marked variety on the national level turned out to be the Kajkavian dialect, while on the Istrian level this turned out to be the speech of the Labin region.