Rheumatic mitral stenosis (MS) is an acquired valvular condition and is rarely associated with Wolff-Parkinson-White (WPW) syndrome. A 51-year-old Caucasian female with known MS presented with syncopal episodes, exertional fatigue and was noted to have atrial fi brillation (AF) with wide-QRS complexes. Old electrocardiogram revealed classical fi ndings of WPW syndrome and wide-QRS was believed to be due to pre-excited AF. Transthoracic echocardiogram demonstrated moderate MS and preserved systolic function. Electrophysiological studies revealed left anterolateral accessory pathway (AP) that was successfully ablated. Pre-excited AF manifests as cardiomyopathy, hemodynamic compromise, multiorgan dysfunction, and ventricular fi brillation. Catheter ablation of AP with or without restoration of sinus rhythm is the recommended therapy, with mitral valve replacement in the same or subsequent procedure.Key words: Mitral stenosis, radiofrequency ablation, rheumatic heart disease, Wolff-Parkinson-White syndrome.