Because congenital ventricular septal defects are of different sizes and locations, their clinical presentation, natural history, and treatment vary greatly. This review discusses the different types of ventricular septal defects commonly seen in adults in the authors' experience and in published literature. Ventricular septal defects are either isolated small defects or larger defects associated with pulmonary stenosis, pulmonary hypertension, or aortic regurgitation. These associations play an important role in the pathophysiologic consequences of the defect, its long-term complications, and treatment options. Knowledge of the different clinical presentations in adulthood and the specific features pertinent to these defects will help in the assessment and the care of adult patients with one of the most common congenital cardiac malformations.