AbstractFive castrated male Iberian pigs (100 ± 2 kg mean live body weight) fitted with T‐shaped ileal cannulas were used to determine ileal digestibility of legume seed meals. The diets were based on defatted soybean (256 g kg−1), lupin (451 g kg−1) or chickpea (731 g kg−1) seed meals and contained similar amounts of digestible energy (14.2–15.1 kJ g−1) and protein (107 g kg−1). Only myristic acid (C14:0) ileal apparent digestibility was higher (p < 0.05) in lupin than in chickpea meal. Ileal apparent digestibility of unsaturated fatty acids (FA) (710–920 g kg−1) was higher (p < 0.05) than that of saturated (480–710 g kg−1) FA for both seed meals. Ileal digestibility of chickpea starch was 850 g kg−1. Ileal digestibility of oligosaccharides (sucrose, raffinose, stachyose, verbascose and ciceritol) in lupin (820 g kg−1) and chickpea (690 g kg−1) was higher (p < 0.05) than that of defatted soybean (510 g kg−1). However, total amounts of oligosaccharides digested were higher (p < 0.05) for lupin and chickpea meals (29.6 and 24.6 g kg−1 feed respectively) than for soybean (15.2 g kg−1 feed). Among individual non‐starch polysaccharide (NSP) sugars, ileal digestibility values for rhamnose and xylose in lupins were higher (p < 0.05) than those for soybean or chickpea. Ileal digestibility of lupin meal NSP (650 g kg−1) was higher (p < 0.05) than those of soybean (560 g kg−1) or chickpea (430 g kg−1). Up to the terminal ileum, higher (p < 0.05) amounts of lupin total NSP (94.1 g kg−1) than for soybean (24.3 g kg−1) or chickpea (27.1 g kg−1) were digested. Lactate, acetate and isobutyrate concentrations were higher (p < 0.05) in ileal contents of pigs fed lupin and chickpea seed meals compared with soybean‐fed animals. It is concluded that higher lactate and short chain fatty acids concentrations in ileal contents of pigs fed lupin or chickpea seed meals compared with soybean are likely to be the result of higher total amounts of lupin NSP and/or lupin and chickpea oligosaccharides digested up to the terminal ileum. This might have a protective effect on Iberian pig's intestinal physiology. Both lupin and chickpea meals are likely to constitute a valuable alternative to defatted soybean in Iberian pig feeding. Copyright © 2005 Society of Chemical Industry