Heligmosomoides vandegrifti sp. nov. (Nematoda, Heligmosomidae) is described from Peromyscus maniculatus (Rodentia, Cricetidae) from Pennsylvania, USA. It differs from its closest congener, H. douglasi, in the number of cuticular ridges (35 vs. 32 in male, 36 vs. 41 in female at mid-body), longer bursal rays 2 in relation to rays 3, and in having smaller spicules (635–740 μm long vs. 1 mm). It is proposed that both H. douglasi and H. vandegrifti sp. nov. are parasites of capture from species in North American arvicoline rodents.