This paper shows that synonyms are inevitable in language. Arabic or English are no exceptions. Both employ synonymy, i.e. synonymy can be within and across languages. It is a controversial issue among linguists of both languages. The study explores the translation of several synonymous lexical items. These samples were taken from Arabic and English specialized dictionaries of synonyms. Through adopting a comparative investigation to these samples, the study explains that the translation of synonyms is problematic in the said languages. The study argues that although Arabic and English have synonyms, each one tackles its synonyms through its own linguistic system, using its own rules. The translation of synonyms in Arabic and English shows that similarities between both languages tend to be less than differences for they differ in different aspects.