The diploma thesis was written on the topic of Linguistic features of administrative texts, because it was noticed increased breach of other styles in everyday use of the administrative functional style. The paper discusses the Croatian language in general, all functional styles are described individually and the administrative functional style is explained separately and in more detail. Numerous characteristics of the administrative style and its importance in the language in general are presented in the thesis. As well, norms and normative levels of the Croatian language are described and the errors that occur on each level. Errors were analyzed from the collected material and presented in their original form. After each example, an error is indicated and, according to normative manuals, an example is given of how it should be written or spoken. For the purposes of the thesis, 67 copies of administrative texts were collected, including petitions, settlements, objections, laws, requests, contracts, etc. Thesis objective was to show the decline in awareness of importance of respecting the norms of the Croatian language and nurturing the diversity of styles. It is evident in the thesis that errors are present at all normative levels and over time errors become established and are no longer considered errors. The paper does not present all the existing problems and there is still room to explore this topic even more thoroughly, but in the hope of improvement, more significant problems are presented that can be solved with a little desire of the individual to advance, both in the language and as an individual.