The PEPS study had the objective of documenting the acceptability and efficacy of propafenone in 1366 treated patients, after correction of chronic or paroxysmal AF, and followed up over one year. All the cases were validated by quality controls performed by the 196 participating cardiologists. All the events during follow up were validated by a committee of independent experts. The patients, aged 67 +/- 11 years, were in sinus rhythm on inclusion. Propafenone was prescribed at the initial dose of 600 mg/day in 65% of patients. The proportion of patients without relapse of AF was 64 +/- 1% at 12 months. After adjustment, the significant predictors of AF relapse were male sex, previous history of chronic AF and prescription of associated drugs. Neither patient age nor propafenone dose significantly influenced AF relapse. Seven deaths (0.5%) occurred during the study of which 3 were of unknown cause. A pro-arrhythmic effect was observed in 8 patients (0.59%) of which 6 had underlying heart disease. The overall frequency of pro-arrhythmic effects, including the 3 deaths of unknown cause, was therefore 0.81%. Tolerance of treatment with propafenone after correction of AF is therefore satisfactory and the frequency of pro-arrhythmic effects is less than 1%. The efficacy of the treatment for the maintenance of sinus rhythm is in accordance with previously published results.