faba bean (fb) seeds can be a good protein-energy component in animal feed. however, the pres-ence of anti-nutritional substances is a negative feature of fb seeds. The aim of this study was to examine the influence of different levels of unprocessed FB seeds in feed on the gut-bone axis and metabolic profile in broilers. Ninety six, 1-day-old Ross 308 broiler chickens were randomly selected to one of the 3 dietary treatments (32 chickens in each, divided into 8 pens with 4 birds per each pen): the control group fed standard diet with soybean meal and without fb seeds, group I fed 8/15% (starter/grower) of high-tannin FB seeds, and group II fed 16/22% of high-tannin FB seeds. bone mechanical examination, hematological and serum biochemical analysis as well histo-morphometry of small intestine and liver tissue were performed. The intake of high-tannin FB seeds, irrespective of their amount, did not alter the bone geometric, mechanical and densitomet-ric parameters nor influenced basal hematological parameters, however it resulted in: decreased serum concentration of total cholesterol and calcium; a reduced longitudinal myenteron of small intestine; increased mucosa and villus epithelium thickness, villus length, thickness and absorptive surface in duodenum; increased number of active crypts in jejunum; unchanged collagen area, in-tercellular space, and total cell number in the liver; decreased number of multinuclear hepatocyte cells. moreover, the livers of birds fed the higher dose of high-tannin fb seeds had lymphocytic infiltrates in portal tracts and sinusoids. Feeding of unprocessed high-tannin FB seeds exerted an influence on the gastrointestinal tract by increased absorptive surface. In conclusion, the dietary inclusion of unprocessed high-tannin fb seeds had no negative effects on broiler growth, tibial bone mechanical properties and intestinal characteristics. unprocessed high-tannin fb seeds may be used in broiler diets, but their dietary levels should not be higher than those discussed.