Atrial fibrillation is associated with cerebral stroke, congestive heart insufficiency and mortality. The present study aimed at evaluating of cognitive disorders in patients with history of atrial fibrillation without cerebral stroke. In a case-control study, 100 patients with first-ever atrial fibrillation seizure without history of cerebral stroke were evaluated. One hundred healthy subjects with normal sinus rhythm matched with the patients in terms of age and gender were regarded as the control group. The case and control groups were followed up for at least one year after occurring of atrial fibrillation. Cognitive disorders were evaluated at the last visit. The case group was consisted of 51 men and 42 women with mean age of 71.08±5.35 years and there were 53 men and 43 women with mean age of 71.34±5.04 years in the control group. Previous history of hypertension, diabetes mellitus, hyperlipidemia, hypercholesterolemia, smoking, consuming of alcohol and warfarin in the case group were 49.5, 23.7, 18.3, 31.2, 14, 7.5 and 9.7% and in the control group 6.4, 35.4, 24, 36.5, 21.9, 13.5 and 12.5%, respectively. In this regard, there was not statistically meaningful difference between these two groups. Dementia was detected in 3 (3.2%) of the case and 1 (1%) of the control group subjects (p = 0.29). Comparing two groups with and without dementia demonstrated that there was not any meaningful risk factor. According to the results, dementia in patients with positive history of atrial fibrillation was more than normal population.