Venous congestion is associated with adverse clinical outcomes in critically ill patients, yet its assessment remains challenging. Recently, the Venous Excess Ultrasound (VExUS) score has shown great potential as a non-invasive tool for assessing venous congestion in cardiac patients. However, the relationship between VExUS and clinical outcomes in patients with sepsis remains understudied. This study aims to evaluate the incidence of venous congestion based on VExUS assessment within the first 5 days of intensive care unit (ICU) admission in critically ill patients with sepsis, and to investigate the association between VExUS and clinical outcomes. We conducted a prospective, observational study in four ICUs, enrolling adult patients with sepsis who stayed in the ICU for at least 24 h. VExUS assessments were performed on days 1 (within 24 h), 3 (48-72 h), and 5 (96-120 h) following ICU admission. Patients were classified according to VExUS score ≥ 2 or < 2. The primary outcome was the prevalence of acute kidney injury (AKI) during ICU stay, while secondary outcomes included 30-day mortality, ICU mortality, and requirement for renal replacement therapy (RRT). Among the 108 patients included, 18% (19 patients) showed VExUS score ≥ 2 on day 1 of ICU admission, and the prevalence progressively decreased to 15% (15 patients) by day 3 and 6% (6 patients) by day 5. The VExUS score ≥ 2 was not associated with AKI (OR 1.82, 95% CI 0.62-5.31, p = 0.274), 30-day mortality (OR 0.82, 95% CI 0.28-2.4, p = 0.711), ICU mortality (OR 1.12, 95% CI 0.41-3.04, p = 0.82), or requirement for RRT (OR 2.29, 95% CI 0.68-7.64, p = 0.179). There was no significant correlation between VExUS and central venous pressure (coefficient: - 0.019, 95% CI -0.01 to 0.05, p = 0.204). In critically ill patients with sepsis, approximately 20% exhibit early (within 24 h of ICU admission) venous congestion, with the prevalence progressively decreasing over the subsequent 5 days. Venous congestion assessed by VExUS was not associated with the occurrence of AKI or with mortality. Chinese Clinical Trial Registry, ChiCTR2200066987. Registered 22 December 2022, https://www.chictr.org.cn/.