This study critically analyzes the regulatory and supervisory frameworks that govern Islamic banks in the dual banking systems of Pakistan, Malaysia, Bahrain, and the UK. We discuss their core regulatory functions and find that conflicting views among Islamic jurists and policymakers have aggravated shariarelated problems. Over the years, the regulatory framework in each country has developed in a certain way. Malaysia and Bahrain have established indigenous governance systems. Islamic banks in the UK still fall under the conventional setup, while in Pakistan, they are governed by an orthodox regulatory framework combined with an evolving Islamic banking regulatory system. However, the effectiveness of the existing regulatory frameworks has never been fully tested by the nascent Islamic banking industry, which remains very conservative.