The authors investigated the left ventricular systolic dyssynchrony (LVSD) parameters in nonischemic dilated cardiomyopathy (DCM) by tissue Doppler echocardiography. A total of 56 DCM patients with normal sinus rhythm and 15 controls were recruited. The patients were subgrouped according to QRS duration (QRSd): QRSd <or=120 milliseconds (group I) and QRSd >120 milliseconds (group II). Ts was defined as the duration from the initiation of QRS to the peak systolic velocity. Patients with DCM had longer intraventricular delay time (IVDT) (101.8 vs 47.4 milliseconds; P<.0001) and standard deviation of Ts (Ts-SD) values (34.9 vs 17.8 milliseconds; P<.0001) compared with controls. There was no difference in IVDT and Ts-SD between the 2 DCM subgroups. The cut-off value for LVSD was 60 milliseconds for IVDT and 25 milliseconds for Ts-SD. The prevalence of LVSD in DCM patients was found to be 78% in group I and 94% in group II. LVSD is common in DCM, regardless of QRSd.