This article undertakes to explain the distinctions between adjectives in Russian and Persian. Russian adjectives are different from Persian ones because of having the following features: gender, number, case and conjugational suffixes. The syntactic and conjugational features of adjectives in the two languages will be presented first. Then, the way adjectives are differentiated from other parts of speech in Russian will be discussed. Later on, the ideas of different linguists about adjectives and the different classifications of adjective will be elaborated. Moreover, the features of adjectives in Russian will be. contrasted with those in Persian. In Persian, sometimes the syntactic function of a word can distinguish an adjective from an adverb. At the end, the results of the research will be presented and discussed.