This review provides an overview of tissue and whole organ decellularization processes, emphasizing the importance of preserving the extracellular matrix (ECM) structure and bioactivity while removing cellular components. Decellularization methods include physical, chemical, and biological agents, each with distinct effects on ECM composition and structure. Effective decellularization depends on factors such as tissue density, desired properties, and clinical application. Common agents include acids, bases, detergents, alcohols, and solvents, each with specific advantages and limitations. Enzymatic agents like trypsin and collagenase are also used, though they may disrupt ECM structure. Physical methods such as freeze-thaw, pressure, and electroporation are employed to enhance decellularization efficiency. Whole organ perfusion is a key technique for maintaining three-dimensional architecture during decellularization. Immersion and agitation are used for tissues without extensive vascular networks. Sterilization of decellularized ECM is necessary to eliminate pathogens and endotoxins. Evaluation of decellularized ECM involves quantifying residual DNA, mitochondrial content, and phospholipids to ensure minimal adverse host responses. Standards for decellularization are crucial for consistent clinical outcomes and successful regenerative medicine applications. The review highlights the need for optimized decellularization protocols to achieve functional ECM scaffolds for tissue and organ replacement.This review provides an overview of tissue and whole organ decellularization processes, emphasizing the importance of preserving the extracellular matrix (ECM) structure and bioactivity while removing cellular components. Decellularization methods include physical, chemical, and biological agents, each with distinct effects on ECM composition and structure. Effective decellularization depends on factors such as tissue density, desired properties, and clinical application. Common agents include acids, bases, detergents, alcohols, and solvents, each with specific advantages and limitations. Enzymatic agents like trypsin and collagenase are also used, though they may disrupt ECM structure. Physical methods such as freeze-thaw, pressure, and electroporation are employed to enhance decellularization efficiency. Whole organ perfusion is a key technique for maintaining three-dimensional architecture during decellularization. Immersion and agitation are used for tissues without extensive vascular networks. Sterilization of decellularized ECM is necessary to eliminate pathogens and endotoxins. Evaluation of decellularized ECM involves quantifying residual DNA, mitochondrial content, and phospholipids to ensure minimal adverse host responses. Standards for decellularization are crucial for consistent clinical outcomes and successful regenerative medicine applications. The review highlights the need for optimized decellularization protocols to achieve functional ECM scaffolds for tissue and organ replacement.