Congenital diaphragmatic hernia (CDH) is a common structural birth defect that affects approximately 1 in 2500 live births. Although the exact etiology of most cases of CDH remains unknown, it is becoming increasingly clear that genetic factors play an important role in many cases of CDH. In this paper, we review critical findings in the areas of clinical and basic research that highlight the importance of genetics in the development of CDH. We also provide practical information that can aid physicians and surgeons as they evaluate and care for patients with isolated, nonisolated, and syndromic forms of CDH and their families.