Introduction During the past two years, we have observed the course of three patients with Ebstein's anomaly* of the tricuspid valve1from birth through infancy. Previous authors2-11have reported on the clinical findings and course of children with Ebstein's anomaly, but as yet only scanty information has appeared in the literature concerning the clinical findings and course of neonates and infants with this cardiac malformation.12-15 It is the purpose of this paper to present in detail the clinical and laboratory findings and the course during the neonatal period and early infancy of the three patients of our experience. The differential diagnosis and management of patients with Ebstein's anomaly are also briefly discussed. Report of Cases Case1.—This male infant, born at the University of Oklahoma Medical Center on Aug 16, 1960, was the fourth term child of a 29-year-old, gravida 6, white female. The mother's pregnancy and