A total of four fragmented strobilae, evacuated spontaneously on January 29, February 29 and March 18 in 1980, from a 45 year-old man living in Kochi Prefecture, were identified as Diplogonoporus grandis (Blanchard, 1894) Liihe, 1899. They were from 111 to 494 cm in length, and from 13.0 to 21.5 mm in the maximum width, all with two rows of complete genital organs, and three containing proglottides exhibiting supernumerary genital organs. The scolex was absent. The patient suffered from diarrhea, abdominal pain and borborygmus. Fresh raw fish was taken frequently by the patient. This is the record of the fourth case from Kochi Prefecture, Japan.