Field experiments were conducted to determine the effects of tank mixing fluometuron or MSMA with sethoxydim or fluazifop on cotton tolerance and large crabgrass control. Postemergence over-the-top application of 1.7 kg/ha of fluometuron reduced cotton lint yield 21% in three of four tests. No yield reduction resulted from postemergence over-the-top application of 1.1 kg/ha of MSMA. Crop injury ratings and lint yields were similar with MSMA or fluometuron applied alone and as tank mixtures with 0.2 kg/ha of either sethoxydim or fluazifol. As compared to sethoxydim or fluazifop applied alone, tank mixtures of sethoxydim or fluazifop plus 1.1 or 2.2 kg/ha of fluometuron were antagonistic on large crabgrass. No antagonism was observed when fluometuron was applied 3 days prior to or 1 day following sethoxydim or fluazifop application. Tank mixtures of 1.1 or 2.2 kg/ha of MSMA plus sethoxydim or fluazifop were antagonistic on large crabgrass in two-thirds of the tests. Antagonism was noted with MSMA applied up to 7 days prior to application of fluazifop but not when MSMA was applied 1 day following application of fluazifop. No antagonism was noted when MSMA was applied 1 day before or after application of sethoxydim.