Field studies were conducted during four seasons to determine the effect of weed covers on Empoasca kraemeri Ross and Moore populations and bean, Phaseolus vulgaris L., yields. Live stands of the broadleaf weed Amaranthus dubius Mart did not have a significant effect on adult leafhopper populations, whereas the grass Leptochloa filiformis (Lam.) Beauv. reduced adult populations throughout the crop cycle. This effect decreased when the weed was killed with paraquat. Live grass weed covers obtained with a mixture of L. filiformis and Eleusine indica (L.) effectively reduced nymphal and adult populations on both a susceptible and a leafhopper-tolerant variety. Pure stands of L. filiformis reduced adult leafhopper populations significantly more than E. indica . Yields of the leafhopper-susceptible variety increased with the use of weed covers in unprotected plots. For the tolerant variety G 02146, only paraquat-treated weeds increased yields. E. indica was more competitive to the leafhopper-susceptible variety than L. filiformis , and both species of grasses affected yields of the leafhopper tolerant variety to the same degree. A search for less competitive weeds or plant species with economic value, capable of reducing leafhopper populations in beans, is suggested.