Species, seasonal abundance, damage, control, and predaceous natural enemies of thrips (Thysanoptera: Thripidae) on cotton, Gossypium hirsutum L., were determined at two sites from 2005 to 2007 in the Lower Rio Grande Valley of Texas. Thrips can stunt growth and reduce yield potential. Seven species of thrips were found. When the cotton field was 0.5 km from commercial onion, Allium cepa L., the predominant species were western flower thrips, Frankliniella occidentalis (Pergande) (61.7%) and onion thrips, Thrips tabaci Lindeman (27.2%). A cotton field 50 km from a commercial onion-growing area was infested with western flower thrips (68.5%) and bean thrips, Caliothrips fasciatus (Pergande) (29.2%). At both fields, cotton seedlings from the cotyledon to 3-4-true leaf stages were most susceptible to onion thrips. Western flower thrips and bean thrips were found predominantly on 5- to 6-true-leaf stage and older cotton. Thrips were found in cotton at the beginning of the growing season and increased gradually in abundance, peaking in mid-May to late June. Predators on cotton were: minute pirate bugs, Orius spp.; lady beetles, Hippodamia spp.; green lacewing, Chrysopa rufilabris (Burmeister); bigeyed bugs, Geocoris spp.; spiders, Argiope spp., and syrphid flies, Syrphus spp. Orius spp. were the most abundant predators (69.5% on nontreated cotton). Heavy rainfall temporarily reduced abundance of thrips on cotton. The systemic insecticides thiamethoxam (Cruiser™) and imidacloprid (Gaucho Grande™) applied to seeds protected cotton from thrips for as long as 30 days after planting.