Acute anuric renal failure was observed in two patients with systemic lupus erythematosus (SLE) during the clinical and serologic active phase of the disease. Renal biopsies, performed during the acute episodes, showed only mild and focal mesangial cell proliferation without deposits. In contrast, tubulointerstitial lesions were predominant. Intense granular immune deposits along the tubular basement membrane, or immunofluorescence examination, were suggestive of immune complex deposition. One of these patients had severe high blood pressure and vascular lesions likely induced by immune complexes. In both, renal function was recovered. Immunologically-mediated tubular and vascular lesions in the course of SLE are discussed.