Option sale, as a special type of sales contract, provides special conditions compared to ordinary sales by creating a right of termination for the parties and uncertainty in the ownership status of the sold item, which, if used correctly, can positive impact on the economy. This type of sale allows the seller to become the owner of the sold item again by returning the price if he is not satisfied with the transaction. On the other hand, there is also the possibility of terminating the transaction for the buyer and a third party. In French law, option sale is also one of the types of special purchase and sale contracts in which the seller acquires the right to repurchase the sold item within a certain period or according to specific conditions. This allows him to potentially regain his ownership, provided that he acts to repurchase within the agreed period. Therefore, this unique feature distinguishes the option sale from other purchase and sale contracts in French law, because in it, unlike ordinary sales, the seller retains part of his ownership rights until the time of redemption. As a result, the advantages of the option sale include greater flexibility in transactions and the possibility of returning to the previous situation in the event of disagreement. In this regard, the effects of the option sale as a complex legal entity require careful analysis and examination in the Iranian and French legal systems examined in this article.