This case illustrates the complementary use of transthoracic echocardiography and transesophageal echocardiography in the diagnosis of partial anomalous pulmonary venous connection. The transthoracic echocardiogram suggested the presence of anomalous pulmonary venous return by demonstrating right heart volume overload and evidence of an intact atrial septum. Transesophageal echocardiography was required to confirm these findings and provide a firm anatomic diagnosis before surgery. This case also emphasizes that a high degree of clinical suspicion for this condition should occur in situations in which apparent right heart volume overload is otherwise unexplained.