While traveling in India, a previously healthy twenty-year-old man had febrile diarrhea. The patient was prescribed medical therapy, and all symptoms were resolved. Fourteen days later, however, similar symptoms recurred. The patient was admitted to a local hospital, but was transferred to our department because of oliguria. Salmonella paratyphi A was isolated from blood and stool specimens, and Giardia lamblia was identified in his stool. The patient's condition was complicated by acute renal failure. The patient received tosufloxacin and metronidazole. Renal function recovered completely without hemodialysis. Paratyphoid fever and giardiasis were resolved. It is suggested that giardiasis exacerbated the paratyphoid fever.