Background— Peculiar aspects of Chagas cardiomyopathy raise concerns about efficacy and safety of sympathetic blockade. We studied the influence of β-blockers in patients with Chagas cardiomyopathy. Methods and Results— We examined REMADHE trial and grouped patients according to etiology (Chagas versus non-Chagas) and β-blocker therapy. Primary end point was all-cause mortality or heart transplantation. Altogether 456 patients were studied; 27 (5.9%) were submitted to heart transplantation and 202 (44.3%) died. Chagas etiology was present in 68 (14.9%) patients; they had lower body mass index (24.1±4.1 versus 26.3±5.1, P =0.001), smaller end-diastolic left ventricle diameter (6.7±1.0 mm versus 7.0±0.9 mm, P =0.001), smaller proportion of β-blocker therapy (35.8% versus 68%, P <0.001), and higher proportion of spironolactone therapy (74.6% versus 57.8%, P =0.003). Twenty-four (35.8%) patients with Chagas disease were under β-blocker therapy and had lower serum sodium (136.6±3.1 versus 138.4±3.1 mEqs, P =0.05) and lower body mass index (22.5±3.3 versus 24.9±4.3, P =0.03) compared with those who received β-blockers. Survival was lower in patients with Chagas heart disease as compared with other etiologies. When only patients under β-blockers were considered, the survival of patients with Chagas disease was similar to that of other etiologies. The survival of patients with β-blockers was higher than that of patients without β-blockers. In Cox regression model, left ventricle end-diastolic diameter (hazard ratio, 1.78; CI, 1.15 to 2.76; P =0.009) and β-blockers (hazard ratio, 0.37; CI, 0.14 to 0.97; P =0.044) were associated with better survival. Conclusions— Our study suggests that β-blockers may have beneficial effects on survival of patients with heart failure and Chagas heart disease and warrants further investigation in a prospective, randomized trial. Clinical Trial Registration— clinicaltrials.gov. Identifier: NCT00505050.