A 65-year-old female with severe mitral regurgitation presenting for mitral valve replacement was found to have a previously undiagnosed aberrant papillary muscle with thickened chordae tendineae inserting into the basal septum during intra-operative TEE. Despite its anatomic location, there was no evidence that the aberrant papillary muscle was contributing to the mitral regurgitation or causing left ventricular outflow tract (LVOT) obstruction. The aberrant papillary muscle was resected during the operation and the patient was separated from cardiopulmonary bypass without complications.