Atrial fibrillation is a common arrhythmia associated with an increased risk for the occurrence of embolism. Recurrences of atrial fibrillation are very frequent and increase the risk for an embolic event. The aim of the present study was to identify the clinical and echocardiographic parameters that are predictive of the recurrence of atrial fibrillation. One hundred and twenty consecutive patients with non-rheumatic atrial fibrillation were followed for 1 year after cardioversion. The following parameters were evaluated: cause and duration of atrial fibrillation, modality of cardioversion, atrial function after cardioversion (peak A wave velocity and A wave integral), left atrial dimension, peak E wave velocity of the transmitral inflow pattern, acceleration and deceleration times, and the integral of E wave. At 1 year, 72 patients maintained sinus rhythm whereas 48 patients had a recurrence of atrial fibrillation. The univariate analysis revealed that the parameter with the strongest influence on the recurrence of atrial fibrillation was the peak A velocity after cardioversion (P < 0.001). The other parameters associated with recurrences were cause of atrial fibrillation (P < 0.001), duration of arrhythmia (P = 0.002), and left atrial dimension (P = 0.05). The modality of cardioversion and the E wave variables did not influence the recurrence of atrial fibrillation. The peak A velocity was smaller in the group of patients who had a recurrence. We suggest that clinical and echocardiographic parameters, such as A wave variables, be used to identify patients at risk for recurrence. These patients should be monitored more frequently and should eventually be treated with antiarrhythmic drugs.