Twenty eight mungbean hybrids derived from 8 x8 diallel excluding reciprocal crosses were studied to know the magnitude of heterosis, heterobetiosis and standard heterosis for yield and its component characters in mungbean. The hybrids with maximum heterosis were ML131 x K851 for 50 % flowering, BM-4 x K-851 for pods per plant, ML-5 x Malviva Jyoti for seeds per pod, ML-5 x Pairy mung and K-851 x TARM-1 for primary branches per plant, Pusa vishal x Malviya Jyoti for days to maturity. Heterosis was significant and positive for seed yield per plant for cross ML131 x TARM-1, (17.01) followed by Pusa vishal x Malviya Jyoti (15.52) hence, heterosis may be of greater significance for crop improvement programme, and it can be exploited for commercial purpose.