Marriage and establishment of a common life is one of the most important acts of kindness given by God to humans.  A marriage compatible with the moral norms will lead to the loftiness of married pair.  Given that marriage does have various aspects, it is necessary to have a comprehensive and correct glance. A mere monetary glance with respect to the marriage will cast a heavy shadow over the common life and the future of the married pair.  Marriage portion (i.e. Mahriyeh) has been established by the Shariah based on the nature of human, whose aim is to enhance and consolidate the relationship between married pair.   Due to the incorrect grasp, nowadays, marriage portion has become a social problem causing marriage to be decreased and divorce to increase.

From the perspective of the Quranic verses and the Islamic Ahadith, there is no limitation for the amount of marriage portion and it is given to the agreement made between the married pair, however, fixing an unreasonable marriage portion because of its conflict with the general rules of the contracts will be invalid. The extent to which a contract may be valid depends on the capability of the parties in doing their obligations embodied in the contract. The heavy marriage portion is not excluded from this rule.  Such a marriage portion will also be invalid due to its conflict with the essential condition for the validity of the contracts namely the power to deliver, in accordance with which the obligor (in the case of the marriage portion, husband) must be able to carry out his obligation. Given the Islamic legal maxim of La zarar, principle 40 of the Constitution of the IRI and the absence of the real intention, the heavy marriage portion which imposes unreasonable and impossible obligation on the obligor would be invalid and inconsistent with the Shariah.

Having relied on the Quranic verses, Islamic Ahadith and Iranian positive laws, this research examines the validity of the heavy and unreasonable marriage portions. Since the foundations upon which the Civil Code of Iran regarding marriage portion is built stem from the Shiite jurisprudence, this research evaluates the approach of the jurisprudence in question to the unreasonable and heavy marriage portions.  The result of this research shows that fixing a heavy marriage portion is invalid because of its conflict with the Shiite jurisprudence, in accordance with which all Islamic ordinances including marriage portion should be justified rationally. This research also recommends some amendments to the relevant provisions in order to solve the problems arising from the heavy marriage portions.

Keywords: Marriage contract, Nature of the marriage portion, Amount of the marriage portion, Heavy marriage portion, Power to deliver the marriage portion.