Vetch (Vicia sativa) and Bitter Vetch (Vicia ervilia) are two grain legumes cultivated in many areas of Iran particularly in the west and north west. They grow under a wide range of environmental condition and are quite resistant to low rainfall. These seeds are traditionally used at a moderate level as a part of a ration for dairy cows and fattening lambs by rural farmers. They are considered as a feed with a high crude protein content. However little is known about their nutritional values for ruminants. In this study the two grain legumes were evaluated in terms of their chemical composition and digestibility in sheep fed straw as a basal diet.