Primary, malignant, cardiac tumors are extremely rare in infants and children. Only a few cases of cardiac rhabdomyosarcoma have been reported in childhood. Echocardiography greatly increases the rate of correct diagnosis of cardiac tumors. There are some cases in the literature which were diagnosed by echocardiography and confirmed histopathologically. In this report, a 13-year-old girl with the clinical findings of cardiac tamponade and who was diagnosed as having a cardiac tumor by two-dimensional echocardiogram is presented An echodense, solid tumor with irregular borders extending especially toward the left ventricular cavity from the apex was demonstrated on echocardiography. The diagnosis was confirmed histopathologically on postmortem examination.