Data of the outcomes of ventricular septal defect (VSD) closure in adults are limited to establish recommendations. Therefore, we reviewed our experience with surgical VSD closure in adult patients. We retrospectively reviewed 152 patients who underwent surgical VSD closure between January 1996 and April 2020. The median age of the patients was 30.5 [interquartile range (IQR) 23.1-42.7] years. The median follow-up duration was 10.9 (IQR 4.8-16.1) years. VSDs were classified according to the Society of Thoracic Surgeons classification as type 2 (n = 66, 43.4%), type 1 (n = 59, 38.8%), and type 4 (n = 27, 17.8%). Aortic cusp prolapse (n = 86, 56.6%) and aortic valve regurgitation (AR, n = 75, 49.3%) were the most common indications for surgical closure. Four patients underwent late reoperation (2.6%) due to AR, infective endocarditis and residual VSD. In the log-rank test, preoperative trivial or more degree of AR (P = 0.004) and coronary cusp deformity (P = 0.031) was associated with late moderate or greater degree of AR. Preoperative moderate or greater AR was associated with reoperation (P = 0.047). Only concomitant aortic valve (AV) repair at the time of VSD closure was a significant risk factor for late significant AR progression in the multivariable analysis. VSD closure in adults can be performed with low mortality and morbidity rates. AR can progress after VSD closure because the aortic cusp may have irreversible damage from long-standing shunt flow exposure. We conclude that VSD with AV deformity or AR in adults should be treated aggressively before disease progression with irreversible damage occurs.