Roundup Ready Cotton technology is of interest to growers across the cotton belt. Experiments were established in North Texas and Southeast Arkansas to evaluate the performance of this new technology. Seed cotton yields were reduced with over-the-top applications at the 12-node cotton growth stage in Arkansas and with a 9 node over-the-top application in Texas when compared to the weed-free check. In Texas, control of common cocklebur, Palmer pigweed, and devil's claw were greater than 80% with single application timings of Roundup ranging from 4 to 10 node. Two applications of Roundup at the 4 and 8 node growth stage controlled ivyleaf morningglory control greater than 80%. Seed cotton yields were greater than 1500 lb/A with a single 6-node application and with 2 application applied at the 4 and 6 node growth stage.