Lung ultrasound (LUS) is a sensitive tool to assess pulmonary congestion (PC). Few data are available on LUS-PC evaluation in patients with severe aortic stenosis (AS) undergoing transcatheter aortic valve implantation (TAVI). The aim of this study was to assess the prevalence and prognostic impact of LUS-PC in patients with severe AS before and after TAVI. We designed a single-centre prospective study in patients referred for TAVI for severe AS (ClinicalTrials.gov identification number: NCT05024942). All patients underwent echocardiography and LUS (according to a simplified 8-zone scanning protocol) the day before and within 72 h after the procedure. The primary endpoint was the composite of all-cause mortality, hospitalization for heart failure and urgent medical visits for worsening dyspnoea at 12-month follow-up. A total of 127 patients were enrolled (mean age 81.1 ± 5.8 years; 54.3% female). Pre-TAVI LUS-PC was documented in 65 patients (51%). After TAVI, the prevalence of LUS-PC significantly decreased as compared to pre-TAVI evaluation, being documented in only 28 patients (22% vs. 51%, p < 0.001) with a median B-lines score of 4 (interquartile range [IQR] 0-11) versus 11 (IQR 6-19) pre-TAVI (p < 0.001). During a median follow-up of 12 (12-17) months, 25 patients (19.6%) met the composite endpoint. On multivariable Cox regression analysis, pre-TAVI LUS-PC was independently associated with cardiovascular events (hazard ratio 2.764, 95% confidence interval 1.114-6.857; p = 0.028). Lung ultrasonography reveals a high prevalence of PC in patients with severe AS undergoing TAVI, which is significantly reduced by the procedure. Pre-TAVI PC, measured by LUS, is an independent predictor of 1-year clinical outcome.