The left atrial appendage (LAA) is one of the major sources of cardiac thrombus formation. The morphology of the LAA correlates with stroke in patients with atrial fibrillation. In this study, we evaluated the correlation between LAA morphology and cardiac function by transthoracic echocardiography in patients with sinus rhythm. We studied 55 patients (36 men, 70 ± 11 years) who underwent cardiac computed tomography and transthoracic echocardiography. The following 4 different morphologies were used to categorize LAA by computed tomography: chicken wing (CW), windsock, cactus, and cauliflower. These morphologies were also classified into CW and non-CW (nonCW) types. There were no significant differences in the left ventricular ejection fraction (63% vs 62%), left atrial (LA) volume (22.2 vs 25.5 ml/m2), and LAA volume (4.3 vs 4.7 ml/m2) between nonCW and CW. Patients with nonCW showed a lower A' velocity (8.0 vs 9.3 cm/s, p < 0.01), worse global longitudinal strain (- 17.2 vs - 20.2%, p < 0.01), lower tissue mitral annular displacement (9.7 vs 11.1 mm, p = 0.01), and lower LAS strain (22.6 vs 34.5%, p < 0.01) by speckle tracking echocardiography than did those with CW. Multiple logistic analysis showed that nonCW LAA morphology was closely associated with lower LAS strain. Furthermore, a change in volume of the LAA during the cardiac cycle was lower in nonCW than in CW. These findings suggest that impaired LA and LAA functions are related to changes of the LAA in patients with sinus rhythm.