Antinutritional factors (ANFs) are a major factor reducing the wider use of underutilized legumes as human food and animal feeds, as a result of the deleterious effects produced by ANFs in man and animals. This study evaluated the levels of some common ANFs in selected in five selected underutilized legumes (ULs) from the Genetic Resources Unit of International Institute of Tropical Agriculture (IITA), Ibadan, Oyo State, Nigeria. The selected ULs were Winged bean (WB) (Psophocarpus tetragonolobus) (Tpt-48), Lima bean (LB) (Phaseolus lunatus) (2006-009), Bambara groundnut (BG) (Vigna subterranea) (TVSU- 1482), Jack bean (JB) (Canavalia ensiformis) (Tce-4) and Sword bean (SB) (Canavalia gladiata) (Tcg-4). All the ANFs were analyzed using standard methods. Statistical analysis was done using descriptive statistics. The results showed that trypsin inhibitors ranged from 13.76+0.02 mg/g (LB) to 39.71+0.04 mg/g (SB), hydrogen cyanides ranged from 9.30+0.02 mg/kg (LB) to 41.41+0.04 mg/kg (SB), oxalates ranged from 0.11+0.00% (BG) to 0.38+0.001% (SB), phytates ranged from 0.24+0.00% (BG) to 0.69+0.002% (SB), saponins ranged from 0.22+0.00% (WB) to 0.35+0.00% (BG), tannins ranged from 0.04+0.00% (WB) to 0.08+0.003% (SB), alkaloids ranged from 0.14+0.00% (WB) to 0.15+0.00% (LB) and haemagglutinins ranged from 25.27+0.01% (LB) to 66.92+0.04% (BG). The study concluded that all the selected underutilized legumes in this study contained antinutritional factors at varying levels and there is a need to investigate the suitable processing methods to either reduce or eliminate the inherent ANFs in these ULs. Keywords: Antinutritional factors, underutilized, legumes, human food, animal feed
