Background: Accurately diagnosing congestive heart failure (CHF) in patients with dyspnea can be difficult because clinical history and physical examination are often nondiagnostic and may be inaccurate, especially when patients have complicated comorbid conditions. Objective: To prospectively assess jugular venous distension on ultrasound (JVD-US) performed by emergency physicians for identifying CHF on echocardiography by the department of cardiology (C-ECHO) in patients with dyspnea. Measurements: This was a secondary analysis of a previously collected data set from a prospective study of JVD-US in ED patients with dyspnea due to suspected CHF. C-ECHO results were obtained and used as the criterion standard. Results: Jugular venous distension on ultrasound had a sensitivity of 99% (95% confidence interval [CI], 92.2%-100%), specificity of 59% (95% CI, 40.9%-74.4%), positive likelihood ratio of 2.4 (95% CI, 1.6-3.6), and negative likelihood ratio of 0.01 (95% CI, 0.0007-0.20) for identifying CHF on C-ECHO in patients with dyspnea. Conclusion: This initial study suggests that JVD-US by emergency physicians is predictive of CHF using echocardiography performed by the department of cardiology as the criterion standard.