Because of its reputed capacity of adaptation to drought, Lathyrus sativus L. is a grain legume of potential interest for southern Italy, and for this reason it was compared with a traditional grain legume, Vicia faba L., in two consecutive growing seasons. Species were field grown both under water stress, rainfed and irrigated conditions and assessed in terms of phenology, growth, yield, water use and water use efficiency. In general, the agronomic behaviour of both crops closely reflected water availability during the growing season and although an advantage of the faba bean was observed, the response of Lathyrus was also satisfactory.