Introduction: In dilated cardiomyopathy (DCM) left ventricular (LV) strain and twist are significantly decreased. However, the rate of attenuation has not been investigated well in patients with varying degrees of systolic dysfunction. Aim: The present study aimed to investigate the relationship between LV deformational and rotational mechanics and conventional and tissue Doppler imaging (TDI) parameters, and to search for a constellation of findings distinguishing patients with severe systolic dysfunction (SSD) in DCM. Methods: Fifty-two patients with heart failure NYHA class III–IV and ejection fraction (EF) ≤45% were prospectively enrolled (mean age 61.8 ± 13.4 years; 36 males, 69%). Severe systolic LV dysfunction was considered as EF <30%. Echocardiography with 2D-speckle tracking analysis was performed. Results: The relationships of global longitudinal strain (GLS) with EF, circumferential strain at mid-level (CSmid), and systolic medial mitral annulus velocity were strong (r = –0.53, 0.67, and –0.56, respectively, p < 0.0001 for all). A good correlation was found between CSmid and EF (r = –0.50, p < 0.0001). There were weak correlations between basal endocardial rotation (BRendo) and EF and CSmid. Multiple regression analysis found GLS (p < 0.0001) and BRendo (p = 0.04) to be predictors of the change of EF. In ROC curve analysis, the cut-off values of GLS –7.2% (AUC 0.81, p < 0.0001), CSmid –7.5% (AUC 0.76, p = 0.002), and BRendo –2.43° (AUC 0.68, p = 0.03) identified SSD. Conclusions: Parameters of LV mechanics were related to conventional and TDI systolic parameters in patients with DCM. The degree of alterations of LV longitudinal and circumferential deformation and basal rotation may identify patients with SSD and a higher risk, and may help in therapeutic decision making.