Herein, we report a case of rheumatic mitral stenosis (MS) with a coronary-cameral fistula (CCF) from the atrial and ramus branches of the left circumflex artery (LCx), revealed by coronary angiography. A 61-year-old woman with a history of rheumatic MS and paroxysmal atrial fibrillation experienced an embolic event with ischemic stroke. Transesophageal echocardiography revealed left atrial appendage (LAA) thrombi. Before mitral valve replacement, left coronary angiography showed a CCF from the atrial and ramus branches of the LCx draining into the left atrium and enhancement of LAA thrombi by contrast staining. During surgery, LAA thrombi were found.