Hulled wheats, some of the oldest domesticated crops, are presently cultivated only in marginal areas of several European and Mediterranean countries. They are of strong interest to several research and development areas, including genetic resources, archaeobotany, plant breeding, rural development, nutritional science and food industry. Until now, cereal scientists have studied only few aspects and small segments of hulled wheat germplasm. A review of the literature concerning grain composition of einkorn (Triticum monococcum L.), emmer (T.dicoccon Schrank) and spelt (T.spelta L.) is presented. Inter-specific differences and intra-specific variation of the most important quality traits are discussed. Assuming that variation is the basis for improvement, the available knowledge indicates the presence of significant variation within each species; moreover, hulled wheat species differ to each other for some characteristics.