Yield responses of two runner peanut cultivars, GK-7 and Southern Runner (SR), to reduced seeding rates and irrigation were evaluated in 1992 and 1993. The cultivars were planted in single rows per bed at 8,12, and 22 seed/m² with a vacuum precision planter and irrigated with a line source irrigation system that delivered irrigation ranging from none to more than an apparent optimum. Total rainfall between planting and digging was 261 mm in 1992 and 338 mm in 1993. Most of the rainfall occurred early with substantial runoff. GK-7 produced as much as 5400 kg/ha pods and SR produced as much as 4600 kg/ha when irrigation was not limiting in 1992. Yields were lower in 1993. There was no significant yield reduction due to reduced seeding rate for either cultivar at any irrigation level. Generally, a reduced seeding rate resulted in slightly higher pod yields. For GK-7, 8 seed/ m² outyielded 22 seed/m² by a maximum of 1129 kg/ha with 673-mm irrigation in 1992 and by 676 kg/ha with 587-mm irrigation in 1993. Pod yield and water use efficiency (WUE) increased with irrigation up to a total of 535 mm in 1992 and 406 mm in 1993. Pod yield increased only slightly and WUE decreased with additional irrigation. No yield or grade advantage of low seeding rate with below-optimum irrigation was evident for either cultivar. When conditions were favorable for plant growth and sufficient time was available for lateformed pods to reach full maturity, plants of these runner cultivars compensated for low plant populations. Planting these and similar varieties at the traditionally high rates may, therefore, not be necessary for optimum pod yield when the growing conditions are similar to those of this study.