Lipoxygenases are the main factors responsible for the grassy-beany flavor of soybeans and soybean products. Three soybean lipoxygenases, L-1, L-2 and L-3 have been identified. Soybean lines lacking L-1 and L-3 or L-2 and L-3 have been bred. In this study, we successfully induced a line lacking L-1, L-2 and L-3 by gamma-ray irradiation. The soybean line lacking all three lipoxygenases did not show any abnormalities when grown under field conditions, suggesting that the lipoxygenases are not essential for normal growth. The development of soybean cultivars lacking seed lipoxygenases should eliminate the need for heat treatment of soybeans to inactivate these enzymes in the processing of soybean food products.