Objectives: The purpose of this study was to determine the effect of beta-blocker therapy on outcomes of hospitalized heart failure (HF) patients enrolled in the Evaluation Study of Congestive Heart Failure and Pulmonary Artery Catheterization (ESCAPE). Background: The effect of beta-blocker therapy on outcomes among hospitalized HF patients is not well documented. Methods: We studied the association between beta-blocker therapy and outcomes among 432 hospitalized HF patients in the ESCAPE trial. Results: A total of 268 patients (62%) were on beta-blockers before admission. These patients had a shorter length of stay (7.9 ± 6.3 days vs. 9.4 ± 6.7 days; p < 0.01) and a lower six-month mortality rate (16% vs. 24%; p = 0.03) compared with those who were not on beta-blockers. Of the patients who were on admission beta-blockers and were discharged alive (n = 263), beta-blockers were discontinued in 54 and significantly modified (>50% dose reduction or changed to alternative beta-blocker) in 28 patients during hospitalization. Factors associated with discontinuation of beta-blockers during hospitalization included respiratory rate >24 breaths/min (30.8% vs. 16.9%; p = 0.03), heart rate >100 beats/min (19.2% vs. 7.3%; p = 0.01), lower ejection fraction (17.9 ± 5.4% vs. 20.2 ± 7.1%; p = 0.04), diabetes (21.2% vs. 37.1%; p = 0.03), and systolic blood pressure <100 mm Hg during hospitalization (70.3% vs. 54.1%; p = 0.03). After adjusting for factors associated with beta-blocker use and those with outcomes, consistent beta-blocker use during hospitalization was associated with a significant reduction in the rate of rehospitalization or death within six months after discharge (odds ratio 0.27, 95% confidence interval 0.10 to 0.71; p < 0.01). Conclusions: Beta-blocker therapy before and during hospitalization for HF is associated with improved outcomes. © 2006 American College of Cardiology Foundation.