Emphasis refers to the intensification or highlighting of a word, a phrase, a clause, a sentence, or a discourse for rhetorical purposes. Lexical emphasis may be implemented by such devices as collocations of synonyms, as well as adverbs of emphasis or terms of absolute certainty, while semantic emphasis comes to be realized through binary conjunctions, adverbs of manner, complements or emphatic states of being, concepts split in distiches, superfluous and non-superfluous morphemes, exclusive-inclusive statements, superimposition, passive verbs, exclamation, exaggeration, post- clausal assimilating attributes, and metaphors. This article aims to compare and contrast emphasis in Persian and Arabic with regard to the facts that statements of absolute certainty and adverbs of manner are syntactic issues, lexical emphasis and binary junctions are matters of morphology, statements of exclusion- inclusion and superimposition are semantic devices, and similes as well as metaphors are rhetorical concepts.