Through a case of a very large left atrial myxoma diagnosed in a 53-year old woman, we feature the complementary value of multimodality imaging. Two-dimensional echocardiography continues to be the principal imaging modality for intracardiac masses due to its accessibility and ability to provide basic information on mass morphology, position, and mobility. Real-time three-dimensional echocardiography offers more precise assessment of tumor size and attachment. Cardiac magnetic resonance allows superior tissue characterization, particularly important in differentiating a myxoma from a thrombus. Appropriate use of these various non-invasive imaging modalities is a safe and comprehensive preoperative diagnostic approach for patients with intracardiac masses.