Trifluralin at 0.6, and 1.1 kg/ha was applied preplant incorporated to the same plots from 1982 through 1986 at Stoneville and Walls, Mississippi. Seed cotton (Gossypium hirsutum L.) yields of 'Stoneville 213' and 'Stoneville 925' in the 0.6 kg/ha treatments were > yields in the hand-hoed herbicide-free treatments for each year at Stoneville, and for each year with both varieties at Walls, except in 1984 with 'Stoneville 825'. When averaged over 5 years at both locations, seed cotton yields were 2900, 2950, and 2780 kg/ha with 'Stoneville 213' and 2960, 2970 and 2920 kg/ha with 'Stoneville 825' for trifluralin at 0, 0.6 and 1.1 kg/ha, respectively. No yield difference was significant. No trends were observed to suggest a buildup over years of trifluralin or metabolites that affected crop stand, crop injury, seed cotton yields or fiber properties. Trifluralin does not cause yield losses in cotton when applied properly at the correct rate.