Background: Although the role of bedside endoscopy for the provision of emergent diagnosis and therapy is well known, the concept of bedside EUS requires further validation. Objective: To evaluate the concept of bedside EUS and assess its impact on patient management. Design: A prospective study. Setting: A tertiary-referral center. Patients: Patients included those with pancreaticobiliary and thoracic disorders who required EUS but who were clinically unstable to be evaluated in the endoscopy suite. Interventions: All procedures were performed by one endosonographer at the patient's bedside by using an EUS cart that was equipped with a therapeutic curvilinear echoendoscope. Main Outcome Measurements: To evaluate the technical feasibility, safety, and impact of bedside EUS in the clinical management of patients. EUS was considered to have a significant impact if a new diagnosis was established and/or if the findings altered subsequent management. Results: Within a 3-month period, 6 patients (4 men; median age 56 years; American Society of Anesthesiologists class III/IV) were evaluated in the intensive care unit by using the mobile EUS cart. Procedural indications were the following: drainage of symptomatic pseudocyst (n = 2), evaluate the cause of cholangitis (n = 2), diagnose and treat a suspected postoperative (distal esophagectomy) fluid collection (n = 1), and provide tissue diagnosis in one patient with a pancreatic-head mass, who presented with intrahepatic bleeding. The procedure was technically successful in all 6 patients (100%), and no complications were encountered. Bedside EUS established a diagnosis of choledocholithiasis (n = 1), mediastinal abscess (n = 1), and pancreatic abscess (n = 1) in 3 patients, and ruled out the presence of choledocholithiasis (n = 1) and pancreatic pseudocyst (n = 1) in 2 other patients. Also, by using bedside EUS, transmural drainage of a pancreatic pseudocyst and mediastinal abscess was successfully undertaken in 2 patients. Bedside EUS had an impact on management in all 6 patients (100%): established a new diagnosis (n = 3), precluded the need for an ERCP and/or other interventions (n = 2), and enabled focused endotherapy (n = 3). Limitations: Small number of patients; a single endosonographer. Conclusions: Bedside EUS is technically feasible, safe, facilitates both diagnosis and therapy, and enables the clinical management of patients who are critically ill. © 2008 American Society for Gastrointestinal Endoscopy.