Field experiments were conducted on farmers' filed, under irrigated condition, on red soils at Manoli Hanumanahatti and Kulageri during summer 1995 and 1996 to know the effect of different levels of copper ore tailings (COT) at 200, 400, 600 and 1000 kg/ha and CuSo₄ at 10, 20, and 30 kg/ ha on groundnut (TMV-2). Pooled data of two years of all the three locations indicated that application of COT @1000 kg/ha significantly increased the pod yield (24.03 q/ha), haulm yield (29.95 q/ha) and oil yield (7.56 q/ha) or groundnut Similarly, application of CuSo₄ @30 kg/ha significantly increased pod yield (21.14 q/ha), haulm yield (27.71 q/ha) and oil yield (6.51 q/ha). Application of COT and CuSo₄ increased the uptake of nutrients. Between CuSo₄ and COT treatments, application of COT proved better. This may be due to the beneficial effect of other plant nutrients such as Fe, Zn and S present in COT.