This article examines the economic essence of the performance efficiency of Islamic financial institutions, their role in the modern financial system, and their significance in financing the real sector of the economy. The paper analyses the fundamental principles of Islamic finance, including the prohibition of riba, gharar and maysir, the reliance of financial transactions on real assets, the equitable distribution of profit and loss, and the compliance of financial operations with Shariah requirements. Particular attention is paid to the economic content, operational mechanisms, risk characteristics and profitability potential of Islamic financial instruments such as musharakah, mudarabah, murabahah, ijarah, salam, istisna, sukuk, qard hasan and takaful. The study substantiates the role of Islamic financial institutions in expanding financial inclusion, supporting small and medium-sized enterprises, financing investment projects and reducing systemic financial risks. The AAOIFI and IFSB international standards are considered important methodological foundations for the legal, accounting and prudential regulation of Islamic financial institutions. The article argues that the efficiency of Islamic financial instruments is reflected in their ability to distribute risks fairly, ensure asset-backed financing, strengthen social responsibility and contribute to sustainable economic development.