© 2018 John Wiley & Sons, Inc. All rights reserved. The role of heterosis in enhancing productivity in food crops is well known. Legume breeders have not been able, however, to take advantage of this genetic phenomenon for a long time, due to biological restrictions, such as the requirement of high seeding rate and the inability to produce large quantities of F1 hybrid seed. Recently, in pigeonpea (Cajanus cajan (L.) Millsp.), a breakthrough has been realized with the development and marketing of the world's first legume hybrid, ICPH 2671. The key for this achievement was breeding and using a stable cytoplasmic nuclear male sterility (CMS) system obtained from the cross between C. cajanifolius, a wild relative of pigeonpea, and the cultivated type. The inherent partial natural out-crossing of pigeonpea was knitted with this CMS system to facilitate economically-viable large-scale hybrid seed production. These developments provided opportunities to overcome the historic stagnant low yield (0.6-0.8 t ha-1) through heterosis breeding. Among hundreds of hybrid combinations tested, a cross between ICPA 2043 and ICPL 87119 (=ICPR 2671), designated as ICPH 2671, was the most promising, with > 40% yield superiority (reaching yields above 3 t ha-1) over the prevalent cultivar 'Maruti', in multi-location, multi-year, on-station trials, as well as on-farm evaluations. The outstanding performance of ICPH 2671 led to its release in 2010 as the first medium duration commercial pigeonpea hybrid in India. Subsequently, two additional pigeonpea hybrids, ICPH 3762 and ICPH 2740 were also released for commercial cultivation in India in 2014 and 2015, respectively. According to recent estimates, in 2015 the CMS-based pigeonpea hybrids were grown over 150,000 hectares in central and southern India. In this review, we summarize the research efforts that led to the milestone of developing the first commercial hybrid in food legumes.