Two Pantanal areas were investigated in Corumbá, Mato Grosso do Sul. The field works were carried out in five trails, in August and December/2011 and April/2012. Seventy-six gall morphotypes were found in 52 host plants, 22 of them were identified at species level and 30 at genus. Fabaceae, Myrtaceae and Sapindaceae were the plant families with the greatest richness of gall. Leaves were the plant organ with the greatest gall richness. Six gall shapes were found - globoid, lenticular, fusiform, cylindrical, conical, and marginal roll. The three first were the most common. Five colors were observed - green, brown, red, yellow, and black. Green and brown predominated. Most were glabrous and one-chambered. These features have been indicated in several Brazilian biomes. Diptera (Cecidomyiidae) were the most frequent gallers. The associated fauna comprised parasitoids (Eulophidae, Braconidae, Eupelmidae, Eurytomidae, Platygastridae, and Pteromalidae), inquilines (Cecidomyiidae: Trotteria Kieffer, 1902, Hymenoptera: Tanaostigmoides Ashmead, 1896, Hemiptera, Lepidoptera and Thysanoptera) and predators (Pseudoscorpionida: Olpiolum medium Beier, 1931, Cecidomyiidae: Lestodiplosini and Hymenoptera: Formicidae). Parasitoids were the most frequent. Multiparatism was observed. Our data represent the first contribution to the knowledge of the associated fauna in the Pantanal.