This article is devoted to phraseological English synonyms, interchangeability and translation equivalence. This paper examines the state of the phenomenon of synonymy in phraseology at present, classifies phraseological units and phraseological synonyms in particular, common translation techniques of idiomatic synonyms, according to different levels of equivalence. The scientific relevance of the work is a synthesis of the linguistic nature of phraseological synonyms, as well as organizing methods of translation. The object of the research, thus, is English and Ukrainian phraseological synonyms. Its subject comprises peculiarities of translation of those synonyms from English into Ukrainian. Phraseological synonyms are those units whose values are close, but thanks to the stylistic and semantic nuances they can be distinguished. Phraseological synonyms are those, with similar meanings, and as a rule, they correlate with the same part of speech, which have partially similar or identical lexical-phraseological compatibility, but are different in meaning, stylistic nuance. This article summarizes different ways of translation of phraseological synonyms from English to Ukrainian, namely phraseological (full phraseological equivalent, partial equivalent and individual equivalent) non-phraseological (lexical translation, calquing, descriptive translation, contextual or selective translation). The purpose of using idiomatic translation is to reproduce the full equivalent in target language.