Liriomyza (Diptera: Agromyzidae) leafminers are polyphagous and important pests of vegetables, field crops, and ornamental plants around the world. Liriomyza cause economic damage to vegetable crops in the Lower Rio Grande Valley of Texas. The current species composition of the leafminers and associated parasitoid species is unknown. Infested foliage and pupae collected from sand-filled trays beneath pepper, Capsicum annum L., plants were sampled in fields in the Lower Rio Grande Valley in fall 2007 and spring 2008. Foliage was stored in ziplocked bags to allow specimen emergence, and sand from the trays was sieved to collect pupae. All specimens that emerged as adults were identified and recorded. Liriomyza trifolii (Burgess) was the dominant species in peppers in the Lower Rio Grande Valley, accounting for 99% of the specimens identified. Our survey showed 20 species of parasitoids from four families (Eulophidae, Braconidae, Figitidae, and Pteromalidae) to be associated with L. trifolii. Neochrysacharis formosa (Westwood) was the most abundant parasitoid during both seasons, accounting for ≈60% of the specimens.