We are developing a mechanical bone testing procedure for medical applications, and have found that properly selected rib segments obtained at autopsy can be tested in bending as straight beams. The component of spongy bone may be disregarded as both its elastic modulus (E) and ultimate stress (σ) are lower than those of whole rib by orders of magnitude. Plastic replica testing shows that the effect of skew, curvature and taper is negligible. In the rib cross-section the compact bone is easily identified by ultraviolet illumination, photographically enlarged tenfold, then divided into small elements on a grid. The moment of inertia is then computed numerically. The findings in 10 radiologically normal subjects suggest that ribs have values for E and σ 15–50 per cent lower than those reported by investigators who tested other bones. Since significantly lower values were found in pathologically demineralized specimens, clinical applicability seems a reasonable prospect.