The scorpion mud turtle (Kinosternon scorpioides) is a small freshwater turtle broadly distributed in South America and commonly consumed in some Brazilian regions. This study aimed to identify the species of helminths that parasitize the digestive tract of K. scorpioides and report infection parameters such as parasite prevalence, mean intensity of the infection, abundance, and the relationship between these nematodes and host body size in this species. We captured 20 adult male K. scorpioides, and 6 animals had nematodes in their gastrointestinal tract. These animals had Serpinema magathi (prevalence = 0.3) and Spiroxys figueiredoi (prevalence = 0.25). There were no correlations between the number of total parasites and carapace length (rs = 0.17, n = 6, P = 0.74) or the length of the gastrointestinal tract (rs = 0.18, n = 6, P = 0.73).