Background: In patients with advanced systolic heart failure, restriction of left ventricular (LV) filling, ventriculoarterial mismatch or mechanical dyssynchrony rather than lower ejection fraction (EF) are more associated with poor prognosis. However, structural determinants of these parameters have not been fully studied. Objectives: We investigated whether patterns of late gadolinium enhancement (LGE) in cardiac magnetic resonance (CMR) affect the ventricular stiffness or ventricular performance in patients with non-ischemic dilated cardiomyopathy (DCM). Methods: Patients with markedly reduced systolic function (LVEF <35%) due to longstanding (> 6 months) non-ischemic DCM underwent CMR after comprehensive echo-Doppler evaluations. Standard deviation of time to peak longitudinal contractions (Ts-SD) in 12 LV segments, stroke volume (SV, ml) and LV chamber volume were measured. Single beat end-systolic elastance (Ees) and arterial elastance (Ea) were measured. Results: Patients (n=49) could be divided into three groups according to LGE patterns as non-LGE group (n=18), non-midwall LGE group (n=13) and midwall LGE group (n=18). There were no differences in clinical characteristics, LV dimemsions, LVEF and Ts-SD among three groups. However, in terms of LV mechanics, midwall LGE group was associated with lower systolic longitudinal velocity (4.6짹1.7 for no LGE vs. 4.3짹1.2 for non-midwall LGE vs. 3.5짹1.0 cm/s for midwall LGE, p=0.025), higher diastolic LV stiffness index (E/Em/SV) (0.41짹0.21 vs. 0.46짹0.31 vs. 0.85짹0.51,ml-1 respectively, p=0.008) and ventriculo-arterial coupling index (Ea/Ees, 3.79짹2.28 vs 4.28짹2.96 vs. 6.05짹3.24, p=0.029). Conclusions: Presence and patterns of LGE is associated with ventricular stiffness and inefficient LV performance in advanced non-ischemic DCM without differences in ventricular synchrony.