The Etymological Dictionary of Czech Phraseology is the first work of its kind in Czech and world linguistics. The analysis of the diachronic aspects of Czech idioms drops behind their synchronic analysis, there is no etymological dictionary of Czech idioms neither special monograph about the history of Czech idioms. This dictionary includes about 4300 idioms, which were discribed in scientific literature in Czech Republic and foreign sources – German, Slovak, Russian, Ukrainian, etc.