As percutaneous mitral valvuloplasty gains wider acceptance, appropriate selection of patients for this procedure continues to be important. The presence of atrial thrombus is a contraindication, and transesophageal echocardiography provides optimal visualization of the left atrium and atrial appendage to assess for the presence of thrombus. This case report describes a patient in whom left atrial thrombus was suspected based on standard precordial echocardiography. After transesophageal echocardiography demonstrated the structure in question to be a normal portion of the left atrial wall, the patient underwent successful uncomplicated percutaneous mitral valvuloplasty. We recommend transesophageal echocardiography in all patients being considered for percutaneous valvuloplasty for mitral stenosis.