We conducted experiments to investigate the immunogenicity of legumes in weaned piglets. Diets contained either casein (control) or an equal protein mixture of casein and raw pea, faba bean, blue lupin, white or black chickpeas, or soya bean meal as protein sources. After four weeks of feeding, jugular blood was collected and plasma analysed for anti-legume protein IgG antibodies. ELISA antibody titres to crude legume protein extracts were higher in the legume-fed piglets than in the controls, except for pea. This was accounted for by higher titres to the 7S, but not to the 11S, legume storage protein fraction. Western blotting revealed many immunogenic proteins corresponding mostly to the 7S family. Minor proteins of chickpea were also found to be highly immunogenic. Overall faba bean and chickpea were the most immunogenic.