Congenital diverticulum of the left ventricle is a very rare disease. Ventricular diverticulum is usually associated with other anomalies including intracardiac and midline thoracoabdominal defect. We describe a case with congenital left ventricular diverticulum presenting as an isolated lesion. A 37-year-old man presented with 4-year history of chest pain. Diverticulum was diagnosed by echocardiography and left ventriculogram.