African Americans with early-onset type 1 diabetes mellitus are at a high risk for severe diabetic nephropathy and end-stage renal disease. In order to determine whether baseline plasma levels of inflammatory markers predict incidence of overt proteinuria or renal failure in African Americans with type 1 diabetes mellitus, we re-examined data of 356 participants in our observational follow-up study of 725 New Jersey African Americans with type 1 diabetes. At baseline and 6-year follow-up, a detailed structured clinical interview was conducted to document medical history including kidney dialysis or transplant, other diabetic complications, and renal-specific mortality. Plasma levels of 28 inflammatory biomarkers were measured using a multiplex bead analysis system. After adjusting for baseline age, glycohemoglobin, and other confounders, the baseline plasma levels of soluble intercellular adhesion molecule-1 (sICAM-1) in the upper two quartiles were, respectively, associated with a three- to fivefold increase in the risk of progression from no albuminuria or microalbuminuria to overt proteinuria. Baseline plasma levels of the chemokine eotaxin in the upper quartile were significantly associated with a sevenfold increase in risk of incident renal failure. These associations were independent of traditional risk factors for progression of diabetic nephropathy. Thus, in type 1 diabetic African Americans, sICAM-1 predicted progression to overt proteinuria and eotaxin-predicted progression to renal failure.