Whether or not beta-blocker therapy should be stopped during acutely decompensated heart failure (ADHF) is unsure. In a randomized, controlled, open labelled, non-inferiority trial, we compared beta-blockade continuation vs. discontinuation during ADHF in patients with LVEF below 40% previously receiving stable beta-blocker therapy. 169 patients were included, among which 147 were evaluable. Mean age was 72 +/- 12 years, 65% were males. After 3 days, 92.8% of patients pursuing beta-blockade improved for both dyspnoea and general well-being according to a physician blinded for therapy vs. 92.3% of patients stopping beta-blocker. This was the main endpoint and the upper limit for unilateral 95% CI (6.6%) is lower that of the predefined upper limit (12.5%), indicating non-inferiority. Similar findings were obtained at 8 days and when evaluation was made by the patient. Plasma BNP at Day 3, length of hospital stay, re-hospitalization rate, and death rate after 3 months were also similar. Beta-blocker therapy at 3 months was given to 90% of patients vs. 76% (P < 0.05). In conclusion, during ADHF, continuation of beta-blocker therapy is not associated with delayed or lesser improvement, but with a higher rate of chronic prescription of beta-blocker therapy after 3 months, the benefit of which is well established.