Left ventricular (LV) diastolic dysfunction often occurs in patients with type 2 diabetes mellitus (DM) independent of atherosclerotic coronary artery disease, myocardial ischemia, and regional wall motion anomalies. Limited information exists on LV myocardial tissue strain in this patient group. We measured 3-dimensional (3-D) parameters of LV systolic and diastolic functions in 28 patients who had type 2 DM (age 33 to 70 years), standard echocardiographic evidence of LV diastolic dysfunction, and normal LV ejection fraction, and 31 normal control subjects (age 19 to 74 years) who had no evidence of cardiac disease, with multislice cine anatomic and tagged magnetic resonance imaging. Three-dimensional analysis of the resulting images showed that peak systolic mitral valve plane displacement was 12% smaller (p = 0.040) and peak diastolic mitral valve plane velocity was 21% lower (p = 0.008) in patients who had DM than in normal controls. Peak systolic circumferential and longitudinal strains and principal 3-D shortening strain were 14%, 22%, and 10% smaller, respectively, in the DM group (p <0.001 for each). Peak diastolic rate of relaxation of circumferential and longitudinal strains and principal 3-D shortening strain were 35%, 32%, and 33% lower, respectively, in the DM group (p <0.001 for each). Thus, LV systolic circumferential, longitudinal and 3-D principal strains, and diastolic strain rates are impaired in patients who have type 2 DM, LV diastolic dysfunction, and normal LV ejection fraction.