Compression-induced shear-mode cracks play an important role in the failure process of rocks. To gain insight into the compression-induced shear-mode cracks in rocks, the initiation and propagation of compression-induced shear-mode cracks are investigated via physical experiments and numerical simulations. The experimental results show that compression-induced shear-mode cracks are a common fracture mode and often lead to final failure. The initiation and propagation of compression-induced shear-mode cracks, as well as the strength of the specimen, can be influenced by the spacing between the flaw tips. Compression-induced shear-mode cracks easily initiate and propagate when the spacing between the two pre-existing flaws is small, whereas a larger spacing can reduce the possibility of shear fracturing and is propitious to the generation of compression-induced tensile-mode cracks. In addition, compression-induced shear-mode cracks initiate and generate later than compression-induced tensile-mode cracks. Furthermore, the fracture angles of compression-induced shear-mode cracks are diverse and complex and can be influenced by the spacing between pre-existing flaws. Numerical simulation results suggest that compressive-shear failure initiates randomly in a shear stress field, becomes more localized with the increased loading and eventually results in compression-induced shear-mode cracks.