We investigated myocardial troponin T (TnT) level as a marker for myocardial injury at various stages of diabetic nephropathy, including end-stage renal failure. One hundred and four diabetic patients were included in this study. These patients were divided into 5 groups as follows: Group I, composed of 41 patients without nephropathy who served as controls; Group II, composed of 15 patients with micro-albuminuria; Group III, composed of 15 patients with macroalbuminuria; Group IV, composed of 8 patients with renal failure who were not receiving hemodialysis; and Group V, composed of 25 patients who were receiving hemodialysis for renal failure. The following markers of myocardial injury were measured in these patients: myocardial TnT, creatine kinase (CK), myoglobin (Mb), and myosin light chain-1 (MCL-1). Our results showed that as the disease state of diabetic nephropathy advanced to renal failure, myocardial TnT levels became elevated. Group V showed significantly higher myocardial TnT levels than either Group I, Group II or Group III. Group IV showed significantly higher myocardial TnT levels than either Group II or Group III. The rate of ischemic changes on electrocardiograms also tended to increase with advance to renal failure in these patients. However, there was no correlation between myocardial TnT levels and serum Cr levels, used as an index for renal function. Myocardial TnT levels had a higher specificity for cardiac muscle than other markers for myocardial injury and are not significantly influenced by renal function. Myocardial TnT may be useful as a marker of myocardial injury for patients with chronic renal failure.