This thesis examines the problems of implementation of the Islamic “zakat” as a system of taxation. In doing so, it seeks to establish coherent and consistent principles for zakat assessment, collection and disbursement, and to measure the Saudi zakat system against these principles. The Kingdom of Saudi Arabia is regarded as the cradle of Islam and it would therefore have been expected that Saudi Arabia would implement zakat correctly. However, this thesis argues that the current implementation of zakat in the Saudi legal system is fundamentally flawed, because it does not comply with a significant proportion of the fundamental principles of zakat. This thesis highlights the problems inherent in Saudi Arabia’s arguably excessive reliance on fatwas for the implementation of zakat. It is argued that these fatwas have rendered contemporary practice of zakat distant from the fundamental principles of zakat. This issue is examined with reference to original sources on zakat (Quranic verses and related statements by the Prophet Muhammad), and Islamic jurisprudence generally. The contention herein will be that the Zakat Regulation in Saudi Arabia requires reform in accordance with the principles identified in this thesis. This thesis begins by examining the concept and principles of zakat, and then establishes the principles of zakat collection, zakat application and zakat disbursement, the zakat practice in Saudi Arabia and its problems, and finally offers recommendations that would render Saudi law conformant with zakat principles.