Ventricular septal defect (VSD) can be associated with various complications such as aortic regurgitation (AR). AR in VSD come from a deficiency or hypoplasia of the conal septum which leads to abnormal apposition in diastole and prolapse of the poorly supported noncoronary or right coronary cusp through the VSD into the right ventricle resembling subpulmonic stenosis and subsequently results in distortion of the aortic valve and progressive AR. AR often increases in severity with age and it indicates a worse prognosis. Therefore, appropriate timing of surgical repair in progressive AR in VSD might be important. Until now, many earlier experiences about surgical repair of AR complicating VSD were on adolescents or young adults. We reported a case of AR in 48-year-old male patient with right coronary cusp prolapse complicating the subarterial type of VSD which was properly assessed by echocardiography and was successfully treated with surgical repair. Right coronary cusp or noncoronary cusp prolapse should be suspected in AR complicating VSD through proper echocardiographic assessment and the surgical repair on VSD and distorted aortic valve should be considered in the old patient, as well as the young.