The aim of this study is to present the main pasture grasses used in Brazil, the process of pasture degradation, pasture phytosociology, some undesirable pasture plants, and pasture restoration techniques. A wide plant availability and the high forage yield of its pastures make Brazil an important producer of plants for animal feed. The great majority of pastures in Brazil contain grasses of the genus Brachiaria, known for its strength and high forage potential. However, the pastures are undergoing constant degradation caused by improper handling, which leads to unsustainability. This is possibly due to extensive and extractive exploitation using a low level of technology and unsuitable management practices. Based on the principle that pastures can be restored, alternative techniques are required to promote improvements in forage quality. For this, it is important to recognize the undesirable pasture plants, which directly interfere with livestock production by competing with forage species for water, nutrients, space and light, as well as producing phytotoxins that prevent or suppress the growth of forage species. In the process of pasture restoration, the main objective is to maintain the vital functions of the ecosystem and to mitigate damage from undesirable plants through the immediate coverage of the soil.