Chlordimeform and aldicarb were evaluated in smallplot field studies for yield enhancement of seven cotton cultivars in 1985-1986 and nine cultivars in 1987. Aldicarb (1.5 lb[AI]/acre) was banded over the row at planting time, and six chlordimeform (0.125 lb[AI]/acre) applications were made on a 5- to 8- day schedule beginning at the second to fourth true leaf stage. High thrips population densities significantly reduced yields and earliness in the no-aldicarb plots, for some cultivars, in 1985 but not in 1987. Aldicarb significantly enhanced earliness in 1985, probably due to thrips control. In 1986 aldicarb significantly increased second-pick yields. Chlordimeform significantly increased yields for Coker 315 and PD-1, but not for the five remaining cultivars, in 1985. In 1986, chlordimeform significantly enhanced earliness and first-pick yields and significantly reduced late July Heliothis spp. damage to squares. Neither aldicarb, cultivar, chlordimeform, nor interactions significantly influenced total yields in 1986 or earliness in 1987. Cultivar was the only factor which significantly influenced total yields in 1987. Results indicated that observed increases in earliness and in total yields probably were due to insect control.