Pastures and weed plants can host plant-parasitic nematodes of economic importance, with the limited yield of pastures representing a continuous challenge for agriculture, especially in the lower Jequitinhonha Valley in southeastern Brazil, where dairy and beef cattle play a crucial role in the local economy. From this perspective, this study aimed to provide information on the population density of plant-parasitic nematodes associated with Panicum maximum cv. Mombaça and Mimosa hirsutissima, weed species commonly found in pasture areas cropped with this grass in the municipality of Almenara, MG, in the Jequitinhonha Valley region of southeastern Brazil. Soil and root samples were collected from the field and placed in plastic bags, which were labeled and taken to the laboratory for nematode extraction. Nematode population densities were estimated in a Peters counting slide under a light microscope, and genera identification was based on morphological traits. In rhizosphere soil (100 g) of P. maximum cv. Mombaça, the highest population densities were observed for Helicotylenchus sp. (3,999), followed by Tylenchus sp. (1,191), Meloidogyne spp. (939), and Pratylenchus sp. (544). In roots (1 g), on the other hand, the highest values corresponded to Pratylenchus sp. (19.6) and Meloidogyne spp. (15.5). However, in rhizosphere soil of M. hirsutissima, the highest population densities were recorded for Tylenchus sp. (2,072), Helicotylenchus sp. (1,883), Pratylenchus sp. (751), and Meloidogyne spp. (307). In contrast, in the roots, the highest values were observed for Meloidogyne spp. (6.9), Tylenchus sp. (4.4), and Pratylenchus sp. (2.7). These findings are essential to take decisions on the management of plant-parasitic nematodes.