Several sulfonylurea herbicides, like foramsulfuron, have been introduced into the turf market. Little is known about tank-mixing herbicides with sulfonylurea herbicides in a turf environment. Carfentrazone is often tank-mixed with herbicides to hasten weed control of herbicides that are slow to act, such as sulfonylurea herbicides. Trials were conducted in 2004 and 2005 to evaluate white clover (Trifolium repens) control with sulfonylurea herbicides with and without carfentrazone. Chlorsulfuron (0.105 kg ai/ha), metsulfuron (0.021 kg ai/ha), and trifloxysulfuron (0.294 kg ai/ha) controlled white clover 96-100 % when applied with or without carfentrazone (0.017 kg ai/ha) at 18 weeks after treatment (WAT) in both years. Foramsulfuron (0.29 kg ai/ha) controlled white clover 58 % in 2004 and 95 % in 2005 at 18 WAT. However, when foramsulfuron was tank mixed with carfentrazone white clover control decreased to 20 % in 2004 and 69 % in 2005. Foramsulfuron was the only sulfonylurea herbicide in these trials that was antagonized by tank-mixing with carfentrazone.