This study investigated the relationship between age and the tension and shear fracture toughness of the femoral neck, femoral shaft, and tibial shaft of aged bone greater than 50 years. Fracture toughness for the different bone locations was shown to be different. Cortical bone of the femoral neck had the highest resistance to crack initiation while the femoral shaft had the lowest. Fracture toughness decreased with age for the femoral shaft and the tibia. The ability of cortical bone of the femoral neck to resist fracture, however, did not decline in bone for this age range.