The compression-compression fatigue behavior of a kind of hip prosthesis made from laminated fiber-reinforced polymeric composite material under biaxial loading was investigated. Specimens were cyclically tested at 59, 69, and 84% of the compressive quasi-static ultimate load. X-ray radiography and a surface replication method were used to record fatigue damage development. Specimens were sectioned after cyclic tests and examined under microscope and scanning electronic microscope for details of surface-related damage features. It was found that the critical damage modes in the neck and mid-stem region of the prosthesis were matrix cracking along fiber directions and microbuckling-type damage in major load-carrying plies, respectively. Occurrences of these different damage modes were attributed to changing stress states, structural geometry, and boundary conditions along the prosthesis. Also, different failure modes were observed among the specimens, which were attributed to the difference in applied load levels.