Skrjabinema kamosika sp. n. (Nematoda: Oxyuridae) is described based on both sexes collected from endemic Japanese serows, Capricornis crispus (Mammalia: Bovidae), of Wakayama Prefecture, western Honshu Island, and Kochi Prefecture, Shikoku Island, Japan. It is readily distinguished from the congeners by having tricuspid sub-interlabial projections in males, large triangular lateral lobes of the lips that do not reach the mouth rim, and a large length ratio of alate/nonalate portions of the tail in females. Close identity in the nucleotide arrangement of ITS2 region between the present material and that from C. crispus of Iwate Prefecture, northern Honshu Island, suggests wide distribution of S. kamosika in Japan. In partial 18S rDNA nucleotide sequence, 0.77% differed from that of Skrjabinema sp. from Capra hircus in the United States.