Cells in their native environment are exposed to a milieu of biochemical and physical forces. Cellular physiology and function are affected by dynamic cell–cell and cell–matrix interactions and communication. Cells bind to the cellular or matrix components through receptors, causing changes in the cytoskeleton, which is then translated into information that controls cell behavior such as proliferation, differentiation, or migration. Physical properties such as matrix stiffness and microtopographies and nanotopographies play an important role in determining cell behavior. This review explores the effect of matrix stiffness on cell behavior, especially when using decellularized extracellular matrix hydrogels as scaffolds for tissue regeneration. Because the mechanical strength of decellularized extracellular matrix hydrogels is lower than that of native tissue, tuning these properties to achieve conditions similar to the in vivo microenvironment can improve the performance of the decellularized extracellular matrix hydrogels as scaffolds in tissue engineering. © 2019