In our clinic, a 16 months old girl presenting the classical findings of EvC syndrome, was operated succesfully. Mitral clefts were repaired by direct suturing, single atrium was repaired by creating a new septum with a pericardial patch and coronary sinüs was left in the left atrium. During the peroperatuar exploration, thimic hypoplasia was recognized. We couldnt find any other cases of EvC syndrome with thimic hypoplasia in the literature.