This research aims to study one of the Shari'a standards of the Accounting and Audit-ing Organization for Islamic Financial Institutions (AAOIFI), the guarantees stand-ard. This standard will be compared with its counterparts in the Shari'a resolution is-sued by the Shari'a board of the Kuwait Finance House (KFH). This study aims to explain the types of financial guarantees. The research adopts the inductive approach by extrapolating the provisions of guarantees in the books of jurisprudence (Fiqh), the AAOIFI Shari'a standards, and the KFH Shari'a resolutions. Also, the analytical ap-proach was used to analyze the statements of early and contemporary jurists regard-ing guarantees, the AAOIFI standard of guarantees, and the KFH Shari'a resolutions related to guarantees. Moreover, a comparative approach was used to compare con-temporary applications of guarantees in the AAOIFI Shari'a standards and the KFH Shari'a resolutions. Among the results reached by this research is that contemporary applications of guarantees and most of their provisions are similar in AAOIFI and KFH. Both took many documentary guarantees and tried to create a kind of balance by preserving the rights of financial institutions and their clients together and within the legal controls of the provisions of guarantees, as both AAOIFI and KFH prohibit-ed the fees for the guarantee while allowing the actual costs to be charged. They did not consider the trustee a guarantor if he could prove that he did not violate it or was negligent. AAOIFI and KFH stated that the guarantee funds should be returned to their owners except to the extent of the actual damage that occurs to the institutions, with the preference of waiving some of their rights in some cases, such as in the �Ar-boun (Earnest money).