Congenital right diaphragmatic hernia is a potentially lethal defect if not properly diagnosed and repaired. Even when it is suspected clinically, recognition may be difficult as initial plain roentgenograms will perhaps appear normal. This report of four cases of herniation of the liver through the right diaphragm stresses the importance of serial roentgenograms and sometimes opaque studies in the diagnosis of this serious congenital defect. Incidence The rarity of congenital right-sided diaphragmatic hernia has been pointed out by several authors. Eppinger (1) presented 635 cases of herniation of the diaphragm; of these only 30 were congenital and on the right side. Kerr and Steinberg (2) reported 13 cases of diaphragmatic hernia with only 3 congenital through the right diaphragm. Case Reports Case I: McK., a male infant, was born prematurely Oct. 3, 1955, after thirty-two weeks of gestation. Birth weight was 4 1b. 1 oz. His condition was good at birth, but a few hours later there was a period of apnea ...