This study was carried out to determine the effects of vinasse on bone strength and some material properties in laying hens with specific amounts of vinasse added to their diets. The study was the first to determine the mechanical properties of laying hens fed a diet supplemented with vinasse. The study was conducted on tibiotarsi of two hundred 94-week-old laying hens which were selected randomly from a commercial farm. Morphometric measurements were made using a digital scale and caliper, and mechanical data were collected from tibiotarsi using a three-point bending test with a compression-tension machine. The laying hens fed with vinasse had higher tibiotarsal length and weight than those in Control group. The groups fed with vinasse were significantly stiffer and had a higher breaking force than Control group (P=0.002, P