Defined as fixed, unchangeable, and hereditary, the family name carries characteristics of historical and geographical identity. They originate from different word classes and different dialectal or homeland idioms. Therefore, their grammatical and lexical characteristics show certain particularities in relation to the standard language norm. Description of morphological and morphosyntactic characteristics of surnames in language manuals is mostly indicated in the case of foreign surnames, cases of declension of female sur-names ending in -a, writing and declension of double surnames. Not rarely, Croatian surnames and their declension patterns are causing problems for Croatian language speakers. This paper analyzes surnames of the region of Zadar, their formation patterns as well as their peculiarities in relation to the standard language form. Analyzed surnames are chosen according to their re-presentation and include all formation suffixes of surnames of the region of Zadar. This paper also tries to define to what extent speakers of the Croatian language have difficulties in defining their declension patterns. The starting assumption of the research study is that, because of their geographical distribution or frequency of use, certain surnames are closer and more familiar to Croatian native speakers. Hence, less deviation from the standard is observed in their declension by comparison to the declension of surnames that are less represented or less widespread.