We studied 73 Thai children with scrub typhus (median age 9 years, range 3-14 years, male:female ratio 1.8:1). Most patients (86%) lived in rural areas. They presented with subacute fever (median, 9 d) with vomiting (35%), hepatomegaly (59%), splenomegaly (18%), and tachypnea (26%). Skin rash (7%), eschar (7%), and history of mite bite were rare. Blood leucocyte counts were usually normal but 19% of patients were thrombocytopenic. Twenty (22%) patients had pneumonia and six (8%) had neurological involvement. Defervescence occurred a median of 1 d and 3 d after initiation of doxycycline and chloramphenicol, respectively, and these responses were more rapid than in those who received other antibiotics or no treatment (P < 0.001). There was one death. Only 55% of the patients were initially diagnosed as having scrub typhus.