Severe leptospirosis usually associates shock, jaundice, renal failure, and thrombocytopenia. Massive hemoptysis due to diffuse alveolar haemorrhage may rarely occur leading to an acute respiratory failure and multiple organ failure. We present the case of an acute respiratory distress syndrome caused by a severe leptospirosis. The severity of the respiratory failure contrasted with the absence of significant liver or renal dysfunction. Bedside open lung biopsy was only consistent with a postinfectious BOOP. The diagnosis was retrospective when the niece of the patient presented with similar inaugural symptoms ten days later after being scratched by a wild rat which was considered by our patient as a pet.