The right of choice is not defined in the law; however, it can be stated that when the subject of a transaction is more than one item and at most three items, and the customer has the right to choose one of these items, this choice is recognized as the right of choice. The period for the right of choice is three days, and the holder of the right of choice must select one item among the maximum of three items as the subject of the transaction. The fundamental question is whether the right of choice falls under the category of cases that grant the right of rescission to the opposing party, and what is its position in the legal systems of Iran and Afghanistan?
 The recognition of the position, source, and nature of the inclusion of this right in contracts in the legal system of Afghanistan and its elucidation in the legal system of Iran, considering that this institution has not been explicitly accepted in the legal system of Iran, are the main objectives of this research.
 The findings of this study indicate that there is no explicit textual basis for the right of choice in the Quran and Hadith, and it is solely derived from the jurisprudential interpretations of Hanafi and Maliki scholars. This institution bears many similarities with the recognized institution of conditional obligations in international law. Although the right of choice is not explicitly stipulated in the legal system of Iran, it can be established in contracts under certain conditions using some provisions of the Iranian Civil Code. It appears that the right of choice can be accommodated within contracts by invoking Article 216 of the Civil Code, where the principle of the supremacy of will is well-recognized. This research follows an analytical and descriptive approach and relies on library research and documentary analysis.