This article discusses idioms and phraseological units with lexical components "truth" and "lie" in English and Kazakh. The purpose of this article is to identify and describe such relevant concepts of modern linguistics as "phraseology", "idiom". The relevance of this article is due to the importance of using phraseological units in everyday communication since it is such properties and qualities of phraseological units as imagery and unity of meaning that make our speech brighter, more emotional, more colourful and expressive, more eloquent, more picturesque regardless of whether we speak English or Kazakh. This article also presents the most famous and popular idioms and phraseologies in English and Kazakh with the components "truth" and " lie " and examined their functioning in the speech of these two languages. Various examples were also given using phraseological units in English and Kazakh. Idioms with these lexical components have a wide range of meanings (mislead the interlocutor, cause moral harm, mystify, deceive, etc.) and are a special subject of reflection of the speaker.Keywords: idiom, phraseology, phraseological units, lexical component, lie, truth, English, Kazakh.