The aim of the present paper is analysis of structure and etymology of the cardinal numerals in Daghestanian languages. It was divided into four parts. The first one is introduction, in which linguistic material and applied research methods were characterized. In the second chapter state of the research was shortly described. Main terms like petrified class morphemes and theory of reverse order (metathesized) stem-roots were explained. Importance of the concept of genetic unity of Ibero-Caucasian languages was stressed as well. The next part of the paper contains studies on structure and etymology of Daghestanian cardinal numerals along with full comparative material from the remaining Ibero-Caucasian languages. Proto-language forms and the intermediate stages of their phonetic development from proto-language to contemporary state were reconstructed. The observed phonetic and morphological changes were meticulously described. Particular attention was paid to internal structure of the investigated numerals in order to detach nominal stems and indivisible roots. Only the indivisible morphemes may be object for historical-comparative research. In the final chapter some interesting perspectives for the future investigations were pointed out. It must be emphasized that the present paper by no means does not exhaust the subject of research and gives new opportunities for further investigations. Keywords: Daghestanian languages, Ibero-Caucasian languages, Nakh, Abkhaz-Adyghe, Kartvelian etymology, cardinal numerals, theory of reverse order (metathesized).