Grain Legumes Improvement Programme (GLIP) is one of the seven research programmes of the Institute. The programme was established in 1975 to carry out genetic improvement of some major legumes in the Southwest agro-ecological zones. The programme is responsible for the development of sustainable production technologies of food legumes to serve the farmers in Southwest Nigeria. Through collaborative efforts, acceptable varieties of grain legumes that are adaptable to Southwest agro-ecologies of Nigeria have been developed over the years. Grain legumes are reliable and safe sources of plant protein in sub-Saharan Africa. They are part of the major crops in the Farming System of Southwest of Nigeria. Some of them fix substantial amount of Nitrogen from the atmosphere, thereby reducing nitrogen fertilizer demand and cost of production. They are also important companion crops in most cereal-legume cropping systems because of the benefits from the residual nitrogen originating from the decay of their leaf litter, roots and root nodules. The yields of various cultivars of grain legumes are however low in the southern agro-ecologies. A number of factors are responsible for the low yield. An average of 500 kg/ha or less of cowpea, for example, is common. Nigeria is the largest producer of cowpea in the world, accounting for 58% of the world total production. Lack of knowledge of good agronomic practices, scarcity of viable seeds for planting, pests and diseases and discouraging poor marginal returns to farmers further worsen the limitations of cowpea production in Southwest Nigeria. There has been continuous decline in production of under-utilized legumes (pulses) in Nigeria during the last two decades. Major crops such as maize, cassava, cowpea and rice have replaced to a considerable extent the area cultivated to pulses. Major problems with pulses includes low yield potential, unstable production levels due to biotic and abiotic stresses, low response to environmental manipulation, lack of research input, defective storage systems and absence of research, value addition and proper marketing facilities. However, their high nutritive values, beneficial effects on soil structure and health, adaption to limiting environmental and soil conditions are capable of sustaining their place in the existing cropping patterns of Southwest ecology. It has therefore become imperative to increase research inputs in terms of improved management practices, modern seed production technology, suitable storage structure and innovative value addition strategies. The Programme has embarked on several research activities to address the above listed challenges.