Patients with type 2 diabetes mellitus (T2DM) are at increased risk for impairments in diastolic relaxation and heart failure with preserved ejection fraction (EF). Recent clinical data suggest that several sodium glucose transporter-2 (SGLT2) inhibitors are found to reduce cardiovascular disease (CVD) events in elderly diabetic patients, but the effect of tofogliflozin, one of the SGLT2 inhibitors, on CVD is unknown. We retrospectively investigated the effect of tofogliflozin on cardiac function in elderly patients with T2DM.Patients received 20 mg of tofogliflozin daily for 1 month. EF, ratio of early filling to atrial filling (E/A), a change in mitral inflow E and mitral e' annular velocities (E/e'), left atrial dimension (LAD) and maximal diameter of inferior vena cava (IVCmax) were measured between baseline and 1 month after the administration of tofogliflozin.Body weight, systolic and diastolic blood pressures significantly decreased, while renin and aldosterone level significantly increased after 1 month of tofogliflozin treatment. Most of the physiological parameters and the level of serum electrolyte did not change significantly. E/A, E/e' and LAD significantly decreased, while no significant changes were observed in EF and IVCmax. The interactions of E/e' between time, gender and age were not significant.The present study suggested that tofogliflozin improved left ventricular diastolic function irrespective of gender and age, while preserving IVC, renal function and electrolyte balance.