Randomized data suggest lenient rate control (resting heart rate <110 beats/min) is noninferior to strict rate control (resting heart rate <80 beats/min) in patients with atrial fibrillation (AF). However, the optimal rate control strategy in patients with AF and heart failure (HF) remains unknown. Accordingly, we performed an observational analysis using data from the Get With The Guidelines-HF Program linked with Medicare data from July 1, 2011, to September 30, 2014. Of 13,981 patients with AF and HF, 9,100 (65.0%) had strict rate control, 4,617 (33.0%) had lenient rate control, and 264 (1.9%) had poor rate control by resting heart rate on the day of discharge. After multivariable adjustment, compared with strict rate control, lenient rate control was associated with higher adjusted risks of death (hazard ratio [HR] 1.21, 95% confidence interval [CI] 1.11 to 1.33, p <0.001), all-cause readmission (HR 1.09, 95% CI 1.03 to 1.15, p <0.002), death or all-cause readmission (HR 1.11, 95% CI 1.05 to 1.18, p <0.001), but not cardiovascular readmission (HR1.08, 95% CI 1.00 to 1.16, p = 0.051) at 90 days. Associations were comparable in patients with poor rate control and with heart rate modeled as a continuous variable. The presence or absence of reduced ejection fraction did not impact the magnitude of most observed associations. In conclusion, in patients with HF and AF, 2 of 3 patients had a heart rate that met strict-control goals at discharge. Heart rates >80 beats/min were associated with adverse outcomes irrespective of left ventricular ejection fraction.