Scrub typhus is a zoonotic disease, caused by Orientia tsutsugamushi, and characterized by a typical primary lesion(eschar), rash and non-specific symptoms such as fever and chills, headache, myalgia. Although it is an acute febrile illness, severe complications of this disease are very rare since the introduction of specific antibiotic therapy. The authors report two cases of scrub typhus complicating acute respiratory distress syndrome. Although appropriate diagnosis and treatment were performed, all two patients expired. They were diagnosed as scrub typhus by travel history, clinical manifestations, eschars, serologic test and polymerase chain reaction(PCR).(Korean J Med 59:544-549, 2000)