Data regarding the associations of anemia (hemoglobin level <13.0 g/dl in men and <12.0 g/dl in women) with clinical outcomes in patients with atrial fibrillation (AF) remains scarce. This study sought to investigate the associations of anemia with the incidences of stroke or systemic embolism, major bleeding, heart failure (HF) hospitalization, and all-cause mortality including its causes, using the data from a Japanese community-based survey, the Fushimi AF Registry. A total of 4,169 AF patients were divided into the 3 groups, based on the baseline hemoglobin level: no (n = 2,622), mild (11.0 to <13.0 g/dl for men and <12.0 g/dl for women; n = 880), and moderate/severe anemia (<11.0 g/dl; n = 667). During a median follow-up of 1,464 days, the incidences of major bleeding, HF hospitalization, and mortality increased with higher rates of cardiac death, in accordance with anemic severity. On multivariate analyses, the higher risk of moderate/severe anemia, relative to no anemia, for major bleeding remained statistically significant (hazard ratio [HR]: 2.00, 95% confidential interval [CI]: 1.48 to 2.72). The risks of those with anemia, relative to no anemia, for HF hospitalization (mild; HR: 1.87, 95% CI: 1.51 to 2.31, and moderate/severe; HR: 2.02, 95% CI: 1.59 to 2.57) as well as for mortality (mild; HR: 1.80, 95% CI: 1.50 to 2.16, and moderate/severe; HR: 2.95, 95% CI: 2.45 to 3.55) were also higher, but not for stroke/systemic embolism. These relations were consistent, regardless of the use of oral anticoagulants. In conclusion, anemia was associated with higher risks of HF hospitalization, mortality, and major bleeding in AF patients.