Hantaviruses are rodent-borne viruses capable of causing human disease. The Seoul virus is a hantavirus that causes hemorrhagic fever with renal syndrome in East Asia. To our knowledge, we report the first domestically acquired case of hemorrhagic fever with renal syndrome caused by the Seoul virus, confirmed by serology testing, reverse-transcriptase polymerase chain reaction, and nucleotide sequence analysis. The patient presented with myalgias and fever, and developed acute renal failure.