This review addresses fracture mechanics of interfaces as related to the process of interfacial crack growth between dissimilar elastic materials. Methods of solution of interfacial crack problems are presented. The concepts of complex stress intensity factors and energy release rate are then discussed. It is suggested that energy release rate, rather than stress intensity factors, is a more appropriate parameter for characterizing the occurrence of interfacial fracture. Topics on the competition between crack penetration and deflection at an interface, delamination of laminated beams, and fracture models for fiber-reinforced composite materials relevant to the debonding of the fiber-matrix interface are reviewed with an emphasis on the energy release rate approach.