Two infants less than 4 months of age underwent repair of apical muscular VSD with left ventriculotomy. First case was 3 months old boy who had already undergone enlargement of the hypoplastic aortic arch with subclavian flap aortoplasty and pulmonary artery banding because of the associated aortic coarctation. Second case was 4 months old Down syndrome girl who associated with ASD and PDA. Both infants were diagnosed the apical muscular VSD with echocardiography and left ventriculography. We performed short longitudinal left ventriculotomy which was parallel to the left anterior descending coronary artery between the diagonal branch and left circumflex artery. VSD was closed with Gore-Tex patch using 6-0 prolene buttress stitches. Post operative echocardiography showed good LV contractile function (Ejection Fraction = 71%, 80%), and no residual interventricular shunt. Left ventriculotomy for the apical VSD closure allowed good exposure and did not reduce the LV function even in infants. Therefore, we concluded that left ventriculotomy was an useful procedure for the apical muscular VSD in infants.