One hundred twenty-two congenital cardiac anomalies were diagnosed in 83 pigs (4.35%) during necropsies of 1906 pigs from one day to four years of age during an 11-month period. The incidence of cardiac malformation was higher at 29 to 56 days of age. Of the 83 pigs with cardiac anomalies, 47 (56%) were male and 36 (44%) were female, and of these, 15 (18%) were purebred and 68 (82%) were crossbred pigs. Of the 15 purebred pigs with cardiac malformation, there were seven Landrace pigs, four Large White pigs, three Duroc Jersey pigs, and one Yorkshire pig; whereas 94% of the 68 crossbred pigs were crossbred among Landrace, Duroc Jersey, and Large White. The 122 cardiac anomalies found in the 83 pigs were: dysplasia of the tricuspid valve in 42 pigs, atrial septal defect in 31 pigs, subaortic stenosis in 22 pigs, ventricular septal defect in nine pigs, persistent common atrioventricular canal in eight pigs, malformation of the moderator band in seven pigs, persistent vena cava in one pig, persistent truncus arteriosus in one pig, and pulmonary stenosis in one pig. The pathological features of the anomalies in swine were similar to those described in small animals and in man. The findings indicate that spontaneous porcine cardiac anomalies might provide models for cardiovascular investigators to study the etiology and pathogenesis of congenital heart diseases in man and other animals.