OBJECTIVES - To measure left ventricular mass (LVM), left ventricular volumes, and left ventricular function (LVF) in a cohort of type 1 diabetic patients and to correlate measures of imaging to NH 2-terminal pro-brain natriuretic peptide (NT-proBNP). RESEARCH DESIGN AND METHODS - In a cross-sectional study, all patients with type 1 diabetes underwent cardiovascular magnetic resonance imaging. We included 63 patients with diabetic nephropathy and 73 patients with normoalbuminuria. RESULTS - All patients had normal global LVF. LVM was increased in patients with diabetic nephropathy compared with patients with persistent normoalbuminuria. Patients with nephrop- athy had smaller left ventricular volumes and increased levels of NT-proBNP. Linear regression analysis in patients with diabetic nephropathy showed that NT-proBNP and creatinine were associated with LVM. CONCLUSIONS - Increased LVM is identified in asymptomatic type 1 diabetic patients with nephropathy compared with normoalbuminuric patients. Elevated levels of NT-proBNP were associated with increased LVM, which are both markers of increased cardiovascular risk.