Two cases of congenital diverticulum of the left atrial appendage are described. The first patient was a 3-year-old girl who had a cerebral embolism. The second patient was a 3(1/2)-year-old girl with signs of pericarditis. Treatment consisted of excising the diverticula. The limited literature on diverticulum of the left atrium as a congenital abnormality is also briefly reviewed.