Left atrial (LA) dissection is a rare complication and is defined as a gap from the mitral or tricuspid annular area to the interatrial septum or left atrial wall. Because of its low incidence, this entity is not fully understood. LA dissection is related to mitral valve surgery as well as coronary artery disease, arrhythmia, trauma, tumor, and spontaneous occurrence. Transesophageal echocardiography is the most useful diagnostic modality for LA dissection, but multimodality investigation supports accurate diagnosis. There are two treatment options for LA dissection: surgical repair and close observation. Surgical repair involves entry closure and internal drainage. The indication for surgery should be based on the clinical presentation.