Lung ultrasound (LUS) is a valid tool for the assessment of heart failure (HF) through the quantification of the B-lines. This study in HF patients aims to evaluate if LUS: (1) can accelerate the discharge time; (2) can efficiently drive diuretic therapy dosage; and (3) may have better performance compared to the amino-terminal portion of B type natriuretic peptide (NT-proBNP) levels in monitoring HF recovery. A consecutive sample of 120 HF patients was admitted from the Emergency Department (ED) to the Internal Medicine Department (Verona University Hospital). The Chest X-ray (CXR) group underwent standard CXR examination on admission and discharge. The LUS group underwent LUS on admission, 24, 48 and 72 h later, and on discharge. The Inferior Cava Vein Collapsibility Index, ICVCI, and the NT-proBNP were assessed. LUS discharge time was significantly shorter if compared to CXR group (p < 0.01). During hospitalization, the LUS group underwent an increased number of diuretic dosage modulations compared to the CXR group (p < 0.001). There was a stronger association between partial pressure of oxygen in arterial blood (PaO) and B-lines compared to the association between PaO and NT-proBNP both on admission and on discharge (p < 0.001). The B-lines numbers were significantly higher on admission in patients with more severe HF, and the ICVCI was inversely associated with B-lines number (p < 0.001). The potential of LUS in tailoring diuretic therapy and accelerating the discharge time in HF patients is confirmed. Until the technique comes into common use in different departments, it is plausible that LUS will evolve with different facets.