We previously reported that incorporation of bean sprout residue into soil stimulated hatching of the soybean cyst nematode (SCN), Heterodera glycines. The objective of this study was to evaluate the effects of short-term growth of mung bean (Vigna radiata), the raw material of bean sprout, and its incorporation into the soil on the density of SCN in soil. When mung bean was grown in pots for 2 and 4 weeks in a SCN-infested andosol, incorporated into the soil and further incubated for 2 weeks, the SCN density decreased markedly. Mung bean was also grown in pots under different moisture conditions. The SCN density decreased in the soils with 48-68 g water, but not with 39 g water (100 g dry soil)−1 in which mung bean grew the poorest. The present study suggests that short-term growth of mung bean may be useful to decrease the density of SCN in soil.