The purpose of this article is to study the obligations of the parties to the law in Iran and Egypt and guarantee its implementation. The main question that has been proposed and examined in this regard is what are the obligations of the seller and the buyer in the law of Iran and Egypt? And how can the guarantee of its implementation be assessed in the law of the two countries? The present article is a descriptive-analytical and examines the question using the library method. The results of this research show that by concluding a series of obligations, the parties will be responsible which must be observed, which have the same view of these obligations in both laws; obligations such as delivery of price and cost are the delivery of both documents.