A 48-year-old woman with systemic sclerosis (SSc) and rheumatoid arthritis was admitted to our hospital because of renal dysfunction. She had no hypertension at the time of admission and mild hypertension for only one and a half months until the time of admission. After admission, she received angiotensin-converting enzyme-inhibitor, but her renal dysfunction did not improve. She then had thrombotic microangiopathy with thrombocytopenia, and was treated with plasma exchange five times, but her renal dysfunction persisted. The renal biopsy specimens showed an arteriosclerotic lesion with intimal thickening and luminal narrowing and ischemic glomerular changes. These findings suggest that there is chronic vascular injury in a patient who has no hypertension with SSc and that once hypertension supervenes, whether severe or not, exacerbation of the vascular injury and renal dysfunction may occur.