Objective: Left ventricular regional synchrony can be analyzed bythree-dimensional echocardiography (3D Echo) as well as by tissueDoppler imaging (TDI). The aim of the study was to compare leftventricular synchrony assessment by both methods. Methods: Aprospective study of 59 patients (36 males, mean age of 50 years ±11 years), 39 with normal cardiac anatomy and eletrocardiography(group 1), and 20 with dilated cardiomyopathy and wide QRS (group 2).Patients underwent 3D echocardiographic – quantification of ejectionfraction (LVEF), volumes and percentage dyssynchrony index (DI)of left ventricular 6, 12 and 16 segments. By TDI we measured leftventricular QS electromechanical interval in the basal segment of themitral valve annulus of the septum, lateral, anterior and inferior walls,as well as tissue dyssynchrony index (%). The statistical analysis wasperformed using Pearson’s correlation coefficient, 95% CI, p < 0.05,linear regression equation and Bland and Altman test. Results: In thenormal group, the correlation coefficient (r) for TDI DI and 3D 6 DIwas 0.5142, p = 0.001; for 3D 12 DI, r = 0.4110, p = 0.009, and for3D 16 DI, r = 0.3761, p = 0.018. In the dilated group, the correlationcoefficient (r) for TDI DI and 3D 6 DI was 0.3920, p = 0.047; for 3D 12DI, r = 0.1344, p = 0.572; and for 3D 16 DI, r = 0.1105, p = 0.643.Conclusion: In both groups, a poor correlation was observed in leftventricular synchrony assessment by 3D Echo and Tissue Doppler.