The type locality of the family Muricidae Monstrotyphis tosaensis (Azuma, 1960) is listed as Tosa Bay, Kochi Prefecture, Japan. Specimens of the species have also been collected from off-Tanabe and off-Shionomisaki, both of Wakayama Prefecture, Japan (Azuma, 1960; Koyama, 1997). We hereby report that additional specimens of the species were newly collected from off- Satsuma Iōjima Island, Kagoshima Prefecture, Japan, at the depths of 239-240 m. This finding records the southernmost occurrence of the species.