A 76-year-old male with multiple myeloma, who was born and had lived in Ehime Prefecture was admitted to our hospital because of high fever. The chest X-p film showed right middle lobal pneumonia. Eosinophilia was detected and a stool smear examination revealed rhabditis form larvae of the nematode. The filaria form larvae of Strongyloides stercoralis were detected by stool culture. Antibiotics and pyruvinium pamoate were administered to bacterial pneumonia and hyperinfection of the strongyloides, respectively. Consequently, pneumonia and strongyloidiasis were promptly improved. It was considered that he was infected with strongyloides in south-east Asia during World-War II and a little autoinfection of this nematode had continued about 50 years. In addition, it was suggested that hyperinfection of strongyloides resulted from the immunosuppressive state induced by the chemotherapy for multiple myeloma.