Cotton production in the Lower Rio Grande Valley of Texas is often reduced by reniform nematodes. Symptoms of cotton grown in these infested soils are stunted, unhealthy plants with low yields. In 1992, field evaluations of several advanced breeding strains were begun to determine the effects of the reniform nematode on yield and fiber quality, and to ascertain yield differences between the experimental strains and a susceptible and resistant check in the presence of reniform nematodes. A second evaluation was initiated in 1994 to ascertain the response of several more recently developed strains. Cotton grown in the reniform-infested plots showed a significant reduction in total lint yield. Several of the experimental strains produced greater lint yields than 'Stoneville 453' (susceptible) and 'LA RN 1032' (resistant). When lint yields were compared between the fumigated and reniform nematode-infested plots, several of the experimental strains had one-half the yield reductions that 'Stoneville 453' sustained due to reniform nematode damage. Results suggest that several of the new experimental strains are capable of producing high yields and possess a greater level of host tolerance or resistance to reniform nematodes.