Mungbean has received little attention of the breeders and geneticists for its improvement. Selection of parents in any breeding programme depends on their ability to combine well and also on the potentially to throw transgressive segregants. The knowledge of heterosis will provide the basic information regarding the breeding methodology to be employed for the varietal improvement, while it also helps in rejecting large number of crosses in first generation itself and selecting only those with high potential. Combining ability provides a useful criterion for selection of desirable parents and hybrids for further exploitation in breeding programme. The information on heterosis for yield and its attributes in hybrids and attempt to assess the relative importance of general and specific combining ability for yield and its components in a diallel set of eight lines of diverse origin excluding reciprocals is presented.