OBJECTIVE In patients with paroxysmal atrial fibrillation (PAF) little information is available about left atrial (LA)function, and there is less information about LA appendage (LAA) function, and about their relations. RESULTS 46 patients were selected for catheter ablation (CA) because of nonvalvular PAF.Transthoracic, tissue Doppler and transoesophageal echocardiography was performed before CA. LA volumes and volume index (LAVI) were calculated. LA function was assessed by LA filling fraction (LAFF), LA emptying fraction (LAEF), systolic fraction of pulmonary venous flow (PVSF) and late diastolic velocities of mitral annulus(Aa,, A5at) LAA function was assessed by peak LAA emptying flow velocity (PLAAEFV). Diastolic dysfunction(DD) was also assessed. Dilated LAVI in 32, LA dysfunction in 20, DD with elevated LV filling pressure in 19 patients was found. Aa,at and Aa,p correlated with LAFF (r:0.53; p<0.001 and r:0.43; p<0.05), LAEF (r:0.51;p<0.001 and r:0.63; p<0.001), PVSF (r:0.49; p<0.001 and r:0.46; p<0.005) and PLAAEFV (r:0.58; p<0.001 and r:0.45; p<0.01). CONCLUSIONS In PAF patients Aa velocity is useful to assess LA function and correlates positively with other TTE derived LA functional parameters and LAA function by TEE derived PLAAEFV.