The aim of this paper is to propose a classification of enantiosems in the Croatian language. In the first part of the paper, basic theoretical assumptions about enantiosemy are presented. A brief overview of the linguistic-philosophical thought about enantiosemy and a brief overview of the organization of linguistic research into this linguistic phenomenon from the end of the 19th century to the present day is provided. Enantiosemy is defined as a linguistic phenomenon whose basic feature is a semantic opposition at the micro level, within the structure of a polysemous lexeme. Since it is a linguistic phenomenon that has only recently become the subject of more serious linguistic research in different languages of the world, the paper refers to the theoretical framework of that part of contemporary literature that turns out to be suitable for the establishment of the classification of enantiosems in the Croatian language. Classifications of enantiosems in different world languages (eg. English, German and Russian) are presented, and it is briefly shown in which ways and how broadly each author understands the mentioned linguistic phenomenon. Given the fact that enantiosemy is the subject of lexical semantics, and then of lexicology and lexicography, a brief comparison of enantiosemy with other types of form – meaning relationships in the lexical system (with homonymy, antonymy and polysemy) is presented. Linguistic regularities that enable the emergence of enantiosemy are presented, such as the relative stability of the language system, the specific relationship between the language system and language usage, and the arbitrariness of the language sign. In the second part of the paper, the emphasis is on presenting the classification of enantiosems based on the corpus collected using different online and printed textual sources (lexicographic and non-lexicographic, non-literary and literary). The collected enantiosems can be divided into two main groups: nominal and evaluative enantiosems. The group of nominal enantiosems consists of incompatible, qualitative, complementary and directional enantiosems. Directional enantiosems are divided into enantiosems based on the contrast between transitivity and non-transitivity, and into conversive and reversible enantiosems. Evaluative enantiosems can be distinguished depending on the connotation of their basic and derived meaning.