Pericardial involvement in malignant disease is fairly common. Usually the various clinical presentations--effusion, tamponade, constriction--occur in patients with known malignancy. Primary malignancy of the pericardium is rare, whereas secondary tumor involvement of the pericardium is more frequently observed. The common secondary solid tumors involving the pericardium are from lung and breast carcinomas; of the nonhematologic malignancies, lymphomas and leukemias are most frequent. A high index of suspicion in patients with malignancy, along with a history, physical examination, x-ray films, ECG, and echocardiography, will often make the diagnosis in a hemodynamically compromised patient. Occasionally, cardiac catheterization and pericardial biopsy are necessary to differentiate malignant pericardial disease from radiation pericarditis and restrictive heart disease. Therapy is dependent on the underlying condition and includes pericardiectomy, chemotherapy to obliterate the pericardial space, and external beam radiotherapy. These therapies are all palliative, but provide months of hemodynamic relief. The underlying prognosis of malignant pericardial disease remains grave.