Specimens of the cystidicolid nematode Salvelinema salmonicola (Ishii, 1916) were collected from the swim bladder of river-resident masu salmon, Oncorhynchus masou masou (Brevoort, 1856), in Yamagata and Shimane prefectures, Honshu, Japan. This nematode is reported herein for the first time from these two prefectures in Japan.