It is varied and rich. The Chaco National Park and Pampa del Indio's, species are the outstanding ones. In the forests and tidelands area, there are 3 species of monkeys: the caraya, the caí and the mirikiná. There are also a lot of carnivorous animals such as the mayuato, the coatí, the ferret, river wolves, otters, etc. The main felines species are: the ocelot, the "yaguarete", the mountain cat, and the puma. Among the rodents is the "carpincho or paibara.

The "tatú carreta" that can reach the size of a dog is a typical animal of the province, you can find out the "tatú de rabo molle", the "mataco, or tatú bola", the black tatú and the "quirquincho". Among the toothless ones there are two families, the big anteaters or "yurumí", and the small anteaters or caguaré. Among the mammals, we can mention the deer or guazupucú, the guazutí, the pecarí and the tapir, etc.

Due to the area's environmental conditions there are a lot of reptiles, terrestrial and sweet water turtles, ophidians and batracians. A great variety of fishes can be found in the river and lagoons, and there is also a varied ornithological fauna.