The objectives of this report were (a) to determine the amount of yield loss of 20 sunflower hybrid varieties in relation to their relative susceptibility to Verticillium wilt under field conditions, and (b) to associate this loss with the relative susceptibility of the s:tme genotypes evaluated by the hypodermic inoculation technique. Signifîcant differences among hybrids were detected for Verticillium wilt score (VWS) evaluated under field conditions, yield (kg/ha), and oil percent in two localities (Henderson and Ballenera). The WVS was negatively correlated with yield in both environments (r=4.68 and -0.44*) but not with oil percent. Depending on the environment evaluated, yield loss per point of the vws can range from 6.5% to 12.2% ilitis taken as percentages over the means of the trials. On the other hand, if it takes into account the extreme values of the VWS at each locality, yield loss for a given hybrid can range from 12 to ca. 50% at Henderson and from 0 to 20% at Ballenera, depending on the degree of susceptibility of the genotype considered. Verticillium wilt scores recorded under greenhouse conditions were positively correlated with the scores obtained under field conditions (r=0.56* and 0.45 for each locality) and negatively correlated with yield (r=0.56* and -0.55*). Both facts indicate that the hypodemic method permits to predict the degree of susceptibility (and its associated reduction in yield) of a given genotype when exposed to this disease under field conditions.