The purpose of this article is to discuss a wide array of traditional Islamic debt instruments in the context of their 'Shari'ah Pareto-Optimality,' i.e., in accordance with their efficiency and permissibility in Islam. This issue is of utmost importance since the Muslim world has gone through centuries of underdevelopment (see Kuran, 1997, 2003, and 2004). There is, therefore, an urgency to revitalize intermediation by adopting efficient financial facilities, permitted in the Shari'ah (Islamic law). This necessitates a critical overview of the traditional financial instruments as described below. [...]