from local clinic due to persistent left flank pain.However, she gradually experienced high fever, dyspnea and general weakness, and was then admitted to other hospital 10 days after falling down.Septic work up was done and prophylaxis antibiotic was prescribed there, and initial CXR revealed bilateral lung patchy infiltrates and consolidations.Abdominal and chest CT with contrast enhancement showed: (1) multiple wedge shape and nodular patches over both lung field, favor septic pulmonary embolism, and (2) left renal infarct with huge sub-capsular hematoma and renal vein thrombosis, favor acute pyelonephritis with thrombophlebitis.Due to the suspicious of renal origin related septic pulmonary embolism, she was referred to our hospital for further management.At our emergent department, ECG was performed to rule out atrial fibrillation related pulmonary embolization.Whole body CT with angiography was performed again, which revealed similar result without other possible origin of the emboli.Emergent left radical nephrectomy was carried out to avoid further thrombus formation.Huge sub-capsular hematoma was found on the specimen, but the renal vein thrombosis disappeared.During the post-operative period in the intensive-care unit, the lung condition gradually improved, and the fever gradually subsided under antibiotic treatment.Extubation was done smoothly a few days later before transferring to the general ward.The patient was then discharged 20 days after the surgery.All culture results in our hospital including blood, urine, renal hematoma and broncho-alveolar lavage were negative findings (blood culture in the first-admitted hospital showed GNB).Final pathology revealed (1) hemorrhagic infarct, and (2) acute suppurative inflammation with abscess formation.Conclusion: Blunt renal trauma with main vascular injury includes laceration, avulsion or thrombosis, is classified as grade V according to the current grading system.However, renal vein thrombosis is also an uncommon complication of acute pyelonephritis or diabetic nephropathy.It was difficult to tell which factor really caused the renal vein thrombosis in this patient, and finally resulted in septic pulmonary embolism.Anticoagulating therapy or thrombolytic therapy is contraindicated in this patient due to the concern of recurrent renal bleeding, and therefore surgical exploration for radical nephrectomy is an optimal choice.