Primary tumors of the heart and pericardium are rare in autopsy series. Considering all age groups, the most common cardiac tumor is the myxoma. They may arise in any of the four chambers or, rarely, on the heart valves. About 90% are located in the atria, with the left-to-right ratio of 4:1. The majority of patients are usually in the age group of 30-60 years. Female predominance has been reported. In this report, we describe a six-year-old boy with right atrial myxoma. A 5x4x3 cm, polypoid, smooth-surfaced, brown-colored tumor was found in the right atrium. It was attached by the stalk to the atrial septum. Microscopically, the tumor had the typical appearance of a myxoma with spindle cells widely spaced by abundant myxoid matrix. The diagnosis was based on histopathological and immunohistochemical findings. Sudden death may occur in patients with atrial myxoma. Death is caused by coronary or systemic embolization or by obstruction of blood flow at the mitral or tricuspid valve.