Volunteer corn can become a weed where beans are grown in succession to corn and there is little information on yield losses and economic threshold for volunteer corn on bean. The objective was to evaluate the effect of volunteer corn density and emergence timing on bean yield and economic threshold. The volunteer corn was planting at 0, 0.5, 1, 2, 4, 8 and 12 plants m-2 in two relatives emergence timing on bean crop (at bean emergence and seven days after bean emergence). The competitive effects on bean yield was high when volunteer corn emerge at bean emergence than late emergence. When volunteer corn emerges at early timing, the yield bean was reduced between 19.6 and 35.5% at one volunteer corn m-2, while for late emergence of volunteer corn, the yield losses ranged from 11.1 and 19.7%. The bean yield had highest impact on economic threshold, indicating low corn densities to justify the control. The increase of grain yield, bean price, herbicide efficiency and reduction in control costs decreased the economic threshold of volunteer corn on bean. The volunteer corn shows high interference potential on bean. The early timing emergence and increase of density of volunteer corn growing with bean causes highest yield losses.