A 65-year-old man was admitted because of high grade fever and cough after 3 days of gathering edible wild plants. Although ceftriaxone was given to him, his symptoms did not improve. His high grade fever escalated after changing the antibiotics (imipenem with erythromycin). His situation further declined with disseminated intravascular coagulation (DIC) and acute respiratory distress syndrome (ARDS). As a result, he was transferred to the Department of Respiratory Medicine 7 days after admission. He was intubated and placed on mechanical ventilation and treated by polymyxin-direct hemoperfusion. The eschar on his chest wall caused us to suspect Tsutsugamushi disease and a blood test confirmed our suspicion. Since the antibodies for Tsutsugamushi were elevated we arrived at the diagnosis of Tsutsugamushi disease with DIC and ARDS. The administration of tetracycline was sufficient to significantly improve his condition. Because its complications are life threatening, when we see a patient with fever and eruptions, it is necessary to keep in mind the possibility of Tsutsugamushi disease. Careful anamnesis and physical examinations are most important for the diagnosis of Tsutsugamushi disease.