Despite recent advances in diagnosis, surgical techniques, and postoperative care of children with congenital cardiac defects, muscular trabecular ventricular septal defects (VSDs) are still a therapeutic challenge. Among these defects, it is more difficult to achieve secure and complete closure of low trabecular or apical VSDs because of the presence of numerous muscular trabeculations overlying the defect. When they are associated with "Swiss cheese"-type of VSDs, it is almost impossible to visualize the true edges of the defect through the transatrial approach. Consequently, there remains an unacceptable incidence of mortality and morbidity when compared to those that occur with closure of the usual perimembranous VSD. Although various techniques for closure of these difficult trabecular VSDs have been attempted, there is still a significant incidence of complications in the surgical management of trabecular VSDs, mostly significant residual shunts, a need for multiple reoperations, and severe left ventricular dysfunction. This article describes the anatomical details and classification of muscular trabecular VSDs. It also reviews several techniques currently utilized and their outcomes.