Systolic anterior motion of the mitral valve (SAM) is well known in the concentric left ventricular hypertrophy or post mitral valvuloplasty. However, SAM has not been reported in Off-pump coronary artery bypass surgery (OPCAB). Preoperatively, SAM in combination with a left ventricular outflow tract obstruction leads to severe cardiovascular destabilization. Moreover, a diagnosis of SAM is very important because the administration of conventional therapy to hypotension can aggravate SAM. We report a patient with un-identified left ventricular wall hypertrophy or mitral valve regurgitation, who was diagnosed with SAM by TEE during OPCAB. This report describes the diagnostic and therapeutic strategies for the perioperative management of SAM.