Chemical composition of eight sweet chestnut cultivars from the three protected designation of origin (PDO) areas in the Trás-osMontes region were studied: Aveleira, Rebordã, Trigueira and Zeive from PDO 'Terra Fria', Demanda, Longal and Martaínha from PDO 'Soutos da Lapa' and Judia from PDO 'Padrela'. Chestnuts were characterised by high moisture content ($50%), high levels of starch (43 g 100 g À1 dry matter -d.m.) and low fat content (3 g 100 g À1 d.m.). Nuts contained significant amounts of fibre (3% d.m.), were rich in K ($750 mg 100 g À1 d.m.), P ($120 mg 100 g À1 d.m.) and Mg ($75 mg 100 g À1 d.m.). Moreover, chestnuts are a good source of total amino acids (6-9 g 100 g À1 d.m.). Amino acid profiles were dominated by L-aspartic acid, followed by L-glutamic acid, leucine, L-alanine and arginine. These results provide additional information about the nutritional value of each cultivar and confirm that chestnuts are an interesting healthy food.