Functional lupin seeds from two different cultivars of white (Lupinus albus L.) and yellow lupin (Lupinus luteus L.) each, were obtained by extraction of α-galactosides. The effect of extraction of α-galactosides from lupin seeds on different nutritional parameters (protein, fat, ash, dietary fibre, starch, sucrose, and vitamins B1, B2, E and C) and antinutritional factors (α-galactosides, trypsin inhibitor activity and inositol phosphates) were studied. In lupin seeds, α-galactosides were effectively removed and processed seeds contained very low amounts of flatulence causing factors (∼0.5-1%). Protein, fat and starch contents showed high retention in processed seeds (up to ∼130%). Sucrose and soluble dietary fibre, however, decreased significantly as a result of processing and retentions ranged from 10% to 60%, depending on the variety studied. Vitamins B 1, B2, E and C were also reduced. Trypsin inhibitor activity was detected only in yellow lupin cultivars and inositol phosphate content was modified slightly after extraction. In summary, the functional lupin seeds, with low contents of α-galactosides, are a product of nutritional importance due to their high protein content, dietary fibre and fat contents as well as acceptable levels of thiamin, riboflavin and vitamin E. They can be incorporated as a proteic source, not only in animal feeding but also in a wide range of foods. © 2005 Elsevier Ltd. All rights reserved.