A 43-year-old female presented with flank pain of two days duration. She had been admitted previously for bilateral lower extremity edema which had not improved with diuresis. Abdominal Imaging showed left ovarian vein thrombosis and left renal vein thrombosis extending into the IVC. Chest imaging revealed right lower lobe segmental pulmonary emboli. Careful review of serial urinalysis during previous admissions revealed significant proteinuria. Confirmatory urine tests followed by a renal biopsy led to a diagnosis of membranous nephropathy. We report a case of acute diffuse thromboembolism due to membranous nephropathy, unmasked by serial abnormal urinalysis.