It is considered a critical condition when a patient presents with fever, jaundice and acute renal failure. A 66-year-old male farmer presented with such critical condition after heavy rain. Biliary tract infection was suspected initially, but the computed tomography of his abdomen showed no abnormality. Because of his history of skin exposure to rain water and his occupation as a farmer, leptospirosis was suspected. Later on, icteric leptospirosis (Weil’s disease) was diagnosed through a positive result of the microscopic agglutination test. After 14 days of antibiotic treatment, renal function and jaundice recovered gradually. Therefore, when a patient presents with fever, jaundice and renal function deterioration, as well as an exposure history of heavy rain, flood or outdoor activity, leptospirosis should be taken into consideration.