Field experiments were conducted in 1996 at three locations in Louisiana to evaluate potential weed control interactions when Roundup Ultra was applied with several insecticides. With respect to barnyardgrass, only the Roundup Ultra-Provado mixture in one experiment reduced weed control 4 weeks after treatment (WAT) when compared with Roundup Ultra applied alone (56 vs. 96% control). Hemp sesbania control observed with the Roundup-insecticide mixtures was equivalent to that obtained with Roundup Ultra alone, which provided 75% control 4WAT. Lorsban, Fipronil, Monitor, or Provado in combination with Roundup Ultra controlled pitted morningglory 2 WAT no more than 80%, which was less than when Roundup Ultra was applied alone (91%).