The 'classic' descriptions of renal histologic abnormalities in patients with hypertensive nephrosclerosis were based upon specimens obtained at autopsy or sympathectomy and were evaluated by light microscopy, without the aid of immunofluorescence or electron microscopy. Patients with renal insufficiency accompanied by elevated blood pressure, hypertensive target organ damage (retinal disease and left-ventricular hypertrophy) and mild proteinuria are typically labelled as having hypertensive nephrosclerosis in the absence of renal biopsy material. Herein, we report the clinical summaries and renal pathology from 2 patients initially diagnosed with hypertensive nephrosclerosis. Glomeruli exhibiting focal and segmental sclerosis and interstitial scarring were present in both cases. The presence of primary renal disease in patients felt to have hypertensive nephrosclerosis is likely more common than currently appreciated. This may result from the lack of renal histologic material and the late presentation of these patients to nephrologists. Misclassification of hypertensive nephrosclerosis would impact greatly on the epidemiology of end-stage renal disease and the evaluation and treatment of patients with chronic renal insufficiency.