Lentil is a popular pulse consumed primarily in Asia. It has a protein content of approx. 28% and also contains high amounts of macro- and micro-nutrients. Lentils are cropped under rainfed conditions and on residual/conserved soil moisture, and their inclusion in rotation benefits succeeding crops as a result of biological nitrogen fixation. This chapter reviews the reviews global production of lentils, and shows how the breeding and use of new varieties with higher yield potential and improved disease resistance has led to increased productivity in many countries. It discusses successful attempts to broaden the genetic base of lentil in South Asia and to cross domestic varieties with wild relatives to access new disease resistance genes. Finally, it considers the scope for breeding new climate-smart varieties of lentil in response to emerging climate changes and variability.