In chronic heart failure (CHF), new-onset atrial fibrillation (AF) is associated with increased morbidity and mortality. We aimed to evaluate the influence of dyslipidemia on the incidence of new-onset AF in patients with CHF.In this single-center observational study, 308 patients with CHF and no history of AF were followed-up for 3 years. Of the 291 patients who attended the 1-year follow-up, 78 had developed AF (AF group; 10 deaths), while 213 had not (sinus rhythm [SR] group). Changes in lipid profile (ΔTC for total cholesterol and ΔLDLc for low-density lipoprotein cholesterol) were analyzed.The groups differed significantly regarding the decrease in lipid levels from baseline to the 1-year follow-up (AF vs SR: for ΔLDLc, 23.35 vs 7.80 mg/dL, P = .02; for ΔTC, 23.95 vs -2.76 mg/dL, P = .001). At the 3-year follow-up, new-onset AF was noted in 21 of the 188 living patients in the SR group. Cox proportional hazards analysis revealed ΔLDLc and ΔTC as independent risk factors for new-onset AF (hazard ratio, 1.018 and 1.013, respectively, per standard deviation increment), with higher incidence of new-onset AF for ΔTC > 9.65 mg/dL (P = .02) and for ΔLDLc > 9.73 mg/dL (P = .005).In CHF, pronounced decrease in LDLc and TC is associated with new-onset AF.