Unilateral pulmonary edema is a distinctly unusual clinical entity that presents interesting and confusing diagnostic challenges. It is usually described as occurring with re-expansion of a collapsed lung after rapid thoracocentesis of pleural air or pleural fluid. Unilateral pulmonary edema as an initial presenting manifestation for heart failure is uncommon and can be confused with other more common causes of alveolar or interstitial infiltrate, which can lead to a significant delay in treatment.