Patients with chronic kidney disease have an increased risk for progression to ESRD. The purpose of this study was to examine factors that predict increased risk for adverse renal outcomes. Cox regression was performed to assess the potential of 38 baseline risk factors to predict the clinical renal composite outcome of 50% or 25-ml/min per 1.73 m2 GFR decline or ESRD among 1094 black patients with hypertensive nephrosclerosis (GFR 20 to 65 ml/min per 1.73 m2). Patients were trial participants who had been randomly assigned to one of two BP goals and to one of three antihypertensive regimens and followed for a range of 3 to 6.4 yr. In unadjusted and adjusted analyses, baseline proteinuria was consistently associated with an increased risk for adverse renal outcomes, even at low levels of proteinuria. The relationship of proteinuria with adverse renal outcomes also was evident in analyses that were stratified by level of GFR, which itself was associated with adverse renal outcomes but only at levels <40 ml/min. Other factors that were significantly associated with increased renal events after adjustment for baseline GFR, age, and gender, both with and without adjustment for baseline proteinuria, included serum creatinine, urea nitrogen, and phosphorus. In black patients with hypertensive nephrosclerosis, increased proteinuria, reduced GFR, and elevated levels of serum creatinine, urea nitrogen and phosphorus were directly associated with adverse clinical renal events. These findings identify a subset of this high-risk population that might benefit from even more aggressive treatment. Copyright © 2006 by the American Society of Nephrology.