Objective：This study aims to evaluate the prognostic value of both left-ventricular systolic and diastolic dyssynchrony in patients with dilated cardiomyopathy（DCM）. Methods：Seventy-four patients with DCM from the First Affiliated Hospital of Nanjing Medical University were enrolled. The phase analysis technique was applied on resting gated short-axis SPECT MPI images to measure left ventricular systolic dyssynchrony（LVSD）and left ventricular diastolic dyssynchrony（LVDD），including phase standard deviation（PSD），phase histogram bandwidth（PBW），and phase entropy（PE）. Patients were divided into cardiac death group and survivor group according to the follow-up data. The Cox regression analysis was applied to determine independent predictors of major adverse cardiac events. Variables with P < 0.10 in the univariate analysis were included in the multivariate Cox analysis to determine independent predictors of major adverse cardiac events. Results：During the follow-up period，29（39.2%）cardiac deaths were observed. Compared to survivor group，patients with cardiac death had lower left ventricular ejection fraction（LVEF）（P=0.011），and more severe LVSD and LVDD（P < 0.01）. The univariate Cox regression analysis showed that hypertension，NT-proBNP，LVEF，left scar burden，systolic PSD，systolic PBW，systolic PE，diastolic PSD，diastolic PBW，and diastolic PE were statistically significantly associated with cardiac death. The multivariate Cox regression analysis showed that systolic PE and diastolic PE were independent predictive risk factors for cardiac death. Conclusion：Both the LVSD and LVDD parameters from SPECT MPI have important prognostic values for DCM patients. Both systolic PE and diastolic PE are independent prognostic factors for cardiac death.