1134 patients presented a first episode of atrial fibrillation (AF) between January 1985 and December 2000. Age average was 58.6 years (15-60). 656 (57.8%) were male and 478 (42.2%) were female. The first etiology of AF was rheumatic carditis (36.1%). AF was idiopathic in 27.7% of cases. Morbi-mortality was significantly higher in patients with AF versus those with sinus rhythm; five years survival was respectively 96% and 85%. Success rate was 70% with electrical cardioversion versus 40% with pharmacological cardioversion. Results of AF reduction was independent of left atrium diameter. Only long standing of AF predicted failure of AF reduction.