Background: In order to gain further insight into age-associated changes of left ventricular (LV) diastolic function, the purpose of the current study was to investigate alterations in LV untwisting with ageing. Methods and Results: The study comprised 75 healthy volunteers, classified into 3 groups: age 16-35 (n=25), 36-55 (n=25) and 56-75 (n=25) years. LV untwisting (as a percentage of peak systolic twist) at 5%, 10%, 15% and 50% of diastole, peak diastolic untwisting velocity, time-to-peak diastolic untwisting velocity and untwisting rate (mean untwisting velocity during the time interval from peak systolic twist to mitral valve opening) were assessed using speckle-tracking echocardiography. Untwisting at 5%, 10%, 15% and 50% of diastole decreased with ageing. Although the peak diastolic untwisting velocity and untwisting rate were not significantly different between the age groups, when normalized for LV peak systolic twist, these parameters decreased with advancing age (both P<0.01). Time-to-peak diastolic untwisting velocity increased with ageing (P<0.01). Conclusions: Impairment of the relative peak diastolic untwisting velocity and untwisting rate, resulting in delayed LV untwisting, may help to explain diastolic dysfunction in the elderly. (Circ J 2010; 74: 101 - 108)