PURPOSE: To evaluate characteristic MR findings of primary cardiac and pericardiac tumors. MATERIALS AND METHODS: There were myxomas (n=7), malignant lymphoma (n=l), lipoma (n=l), and pericardiac mesotheliomas (n=2). We analyzed location, size, shape, signal intensity, contrast enhancement, and associated findings of adjacent structures such as pericardiac and pleural effusion, and mediastinal lymph node enlargement. RESULTS: Locations of the myxomas were left atrium in four cases, left ventricle in one, right atrium in one, and right ventricle in one. Mean diameter was 3.5cm (range, 2-7cm). They were polypoid or Iobulated in shape, and attached to interatrial or interventricular septurn in all cases except in right atrial myxoma which was attached to lateral wall. Their peduncles were demonstrated in three left atrial myxomas. The signal intensities were iso or slightly high on T1-weighted images and high on T2-weighted images. Pleural and pericardial effusions were shown in the three cases. Malignant lymphoma was manifested as large mass in right ventricle infiltrating to right atrium, interventricular septum, right paratracheal and retrocardiac area. It had slightly high intensity in both T1- and T2-weighted images with a strong contrast enhancement and associated with both pericardiac and pleural effusion. Lipoma was polypoid in shape and attached to lateral wall of left ventricle with bright T1 and high T2 signal intensity. Pericardiac mesothelioma was manifested as a pericardiac and atrial mass with diffuse irregular uneven thickening of pericardium which had iso signal on T1- and high T2-weighted images with moderate contrast enhancement. Conculsion: MR imaging is a very useful method in demonstration of the location, extent, tissue characteristics of the mass, and relationship with its adjacent structu res in evaluation of cardiac and pericardiac tumors.