Vascular calcification is one of the mechanisms mediating the higher mortality risk associated with the hyperphosphatemia of chronic kidney disease. Though common, and often severe in non-dialyzed proteinuric diabetics, there are no studies on the prognostic significance of coronary artery calcification in early stage type 2 diabetic nephropathy. Here we determine this significance in 225 proteinuric diabetic patients (mean age 57 years, mean estimated glomerular filtration rate (eGFR) 52 ml/min per 1.73 m2 and a median urine protein–creatinine ratio of 2.7). Coronary artery calcification, measured by electron beam computed tomography, was diagnosed in 86% of the patients, the severity of which correlated with older age, male gender, and white ethnicity. However, no association was found between eGFR, serum calcium, phosphorus, parathyroid hormone, or 25-hydroxy vitamin D. Over an average follow-up of 39 months, 54 patients died. A graded relationship between the severity of calcification and all-cause mortality was consistently demonstrated on both univariate and multivariate analyses. Patients in the highest quartile of calcification score had a 2.5-fold higher risk for death. Our results show the severity of coronary artery calcification early in the course of chronic kidney disease is an independent predictor of all-cause mortality. Additional studies need to determine whether altering the natural history of coronary artery calcification in early chronic kidney disease prolongs survival.