Ventricular Septal Defect (VSD) complicates approximately 1-5% of patients presenting with penetrating chest trauma, however not all VSDs are evident at the time of initial presentation to the emergency department. Acute closure of traumatic VSDs is indicated in patients with a large defect and haemodynamic compromise, however closure may be delayed in smaller defects in order to minimise operative time, reduce operative mortality and allow for recovery from the initial trauma. We describe the case of a previously healthy 23 year-old Caucasian man who presented in extremis following stab wounds to the precordium. After emergency cardiopulmonary bypass and closure of lacerations to both the left and right ventricles, postoperative trans-thoracic echocardiography (TTE) noted a restrictive intramuscular VSD with a high velocity left to right shunt, initially managed conservatively. Elective surgical closure was performed 10 months after the initial injury through a right ventriculotomy using 4–0 Proline sutures reinforced with Teflon pledgets. Despite excellent clinical recovery, 3-month follow-up TTE noted a residual VSD in the mid apical septum. However, given the presence of minimal left to right shunt and the small size of the defect, the patient was managed conservatively with annual review and repeat transthoracic echo. This case highlights the potential pitfalls in both the diagnosis and management of traumatic VSDs particularly where the patient presents in extremis with other life-threatening injuries. Furthermore, it exemplifies the importance of a multidisciplinary approach when planning any elective intervention. Regardless of the management strategy, repeated re-assessment and re-evaluation is vital following penetrating cardiac trauma, and vigilant long-term follow-up is of paramount importance in these cases.