Objective To investigate the characteristics of cognitive dysfunction in the elderly patients with atrial fibrillation (AF). Methods A retrospective analysis was made of 165 elderly patients hospitalized in the Department of Geriatric Cardiology of Beijing Friendship Hospital from January 2016 to December 2017, who were divided into AF group (83) and non-AF group (82). Cognitive function was assessed using Montreal Cognitive Assessment Scale (MoCA) and Mini-Mental State Examination Scale (MMSE). SPSS statistics 24.0 was used for data analysis, and Student′s t test, nonparametric rank sum test or Chi-square test for comparison between the groups. Results MoCA assessment showed that 71.1% (59/83) in the AF group had cognitive dysfunction against 56.10%(46/82) in the non-AF group (P<0.05). Compared with the AF group, the non-AF group scored lower in the visuospatial and executive function [(3.17±1.64) vs (3.96±1.23)], language [(1.98±1.00) vs (2.34±0.95)], abstraction [(1.27±0.75) vs (1.56±0.67)] and orientation [(5.20±0.85) vs (5.50±1.10)] and total score [(20.27±6.83) vs (23.16±5.78)], the differences being statistically significant (P<0.05). MMSE showed that 31.3% (26/83) in the AF group had cognitive dysfunction against 18.3% (15/82) in the non-AF group with a difference of statistical significance (P<0.05). Compared with the AF group, the non-AF group had lower scores in the time orientation [(3.92±1.60) vs (4.40±1.20)], place orientation [(4.66±0.89) vs (4.89±0.45)], attention and calculation [(3.39±1.80) vs (3.94±1.40)], object naming [(1.98±0.15) vs (2.35±0.78)], and graphic description [(0.73±0.44) vs (0.90±0.30)], and total score [(24.90±5.87) vs (26.79±4.20)], the differences being statistically significant (P<0.05). Conclusion Cognitive dysfunction in AF patients featuresmainly in visuospatial and executive function, language, abstraction, time and place orientation, attention and calculation, object naming, and graphic description, which greatly affects the daily life of the elderly. Active recovery or maintenance of sinoatrial nodular rhythm in AF patients can improve their quality of life.