Although an increased heart rate (HR) is a strong predictor of poor prognosis in cases of chronic heart failure (HF), the clinical value of HR as a predictor in acute decompensated HF (ADHF) is unclear. Seventy-eight patients with nonischemic dilated cardiomyopathy (NIDCM) with sinus rhythm who were first hospitalized for ADHF from 2002 to 2010 were retrospectively investigated after exclusion of patients with tachycardia-induced cardiomyopathy. The patients were divided into two groups stratified by HR on admission with a median value of 113 beats/min (Group H with HR ≥ 113 beats/min; Group L with HR < 113 beats/min). Despite similar backgrounds, including pharmacotherapy for HF, HR changes responding to titration of β-blocker (BB) therapy and myocardial interstitial fibrosis, left ventricular (LV) ejection fractions improved more significantly 1 year later in Group H than in Group L (57 % ± 11 % vs. 46 % ± 12 %, P < 0.001). Cardiac event-free survival rates were also significantly improved in Group H (P = 0.038). Multiple regression analysis revealed that only the peak HR on admission was an independent predictor of LV reverse remodeling (LVRR) 1 year later (β = 0.396, P = 0.005). High HR on first admission for ADHF is a strong predictor of LVRR, with a better prognosis in the event of NIDCM in response to optimal pharmacotherapy, independent of pre-existing myocardial damage and subsequent HR reduction by BB therapy.