This master’s thesis includes Croatian and Slovenian idioms that fit the meaning of the concepts of WEALTH and POVERTY. In the introductory part of the paper, the terms idiom and phraseology and the development of the discipline in Croatia and Slovenia are defined. Given that the analysis includes opposite mental images of poverty and wealth, a special chapter will be devoted to phraseological antonymy (Šarić, 2007). Furthermore, in the central part of the work, collected idioms, found in Slovenian and Croatian printed and online-dictionaries, are divided into groups according to idiomatic meaning or main component. The meaning, motivation and origin of idioms and their stylistic characteristics are investigated. In the last part of the analysis, the typology of interlingual phraseological equivalence is elaborated and defined in more detail (Čagalj, Svitkova 2014) according to four types: (1) complete (absolute) equivalence (Cro. živjeti kao mali bog – Slo. živeti kot mali bog), (2) partial/relative equivalence (Cro. roditi se sa zlatnom žlicom u ustima – Slo. roditi se s srebrno žlico v ustih), (3) semantic equivalence (Cro. jedva sastaviti/sastavljati kraj s krajem – Slo. težko se prebijati) and (4) zero equivalence (lova do krova). The aim of this thesis is to investigate the similarities and differences in the Croatian and Slovenian languages when it comes to idioms describing wealth and poverty.