Pulmonary ultrasound is a simple diagnostic tool with immediate results for the assessment of pulmonary congestion in patients with heart failure (HF), allowing optimization of treatment by monitoring the dynamic changes identified. We aimed to evaluate the prognostic significance of the presence of B lines detected by lung ultrasound during hospitalization for heart failure. A search was conducted for scientific articles in PubMed, Embase, Google Scholar, and Cochrane databases including clinical trials, reviews, systematic reviews, and original articles that were related to the prognostic value of lung ultrasound in patients with HF in the last 5 years from 2016 to 2021. Studies including individuals aged ≥18 years evaluating the prognostic value of lung ultrasound in HF were included. Fourteen articles met inclusion criteria for analysis (three reviews, three systematic reviews with meta-analysis, six prospective studies, and two retrospective studies). The presence of more than 30-40 B lines at admission were considered a risk factor for readmission or mortality as was persistent pulmonary congestion with the presence of ≥15 B-lines. The presence of pulmonary congestion detected by lung ultrasound in acute heart failure has prognostic significance in terms of mortality and hospital readmission. Clinical trials are needed to evaluate whether diuretic therapy guided by lung ultrasound and the presence of B lines can reduce readmission and mortality in these patients.