A wide spectrum of congenital and acquired abnormalities can affect the superior vena cava (SVC). Congenital anomalies can present either as incidental findings or be associated with underlying cardiac abnormalities; these include left-sided or double SVCs and anomalous venous drainages. Acquired conditions involving the SVC, including SVC obstruction syndrome, can be secondary to extrinsic compression or intrinsic occlusion. The CT appearances, the incidence, and associations of these conditions are discussed.