Considerable advances have been made to determine the failure biomechanical properties of the human thoracic spinal column and its components. Except for a few fundamental studies, there is a paucity of such data for the costovertebral elements. The present study was designed, to determine the biomechanics of the human thoracic spine ribs from a large population. Seventh and eighth ribs bilaterally were tested from 30 human cadavers using the principles of three-point bending techniques to failure. Biomechanical test parameters included the cross-sectional area (core, marrow, and total), moment of inertia, failure load, deflection, and the Young's elastic modulus. The strength-related results indicated no specific bias with respect to anatomical level and hemisphere (right or left), although the geometry-related variables demonstrated statistically significant differences (p < 0.05) between the seventh and the eighth ribs. This study offers basic biomechanical information on the ultimate failure and geometric characteristics of the human thoracic spine ribs.