Cardiac emergencies may be encountered during the management of patients with cancer, both in those with underlying cardiovascular disease and those with no previous history of cardiac problems. Both surgical and medical cancer treatment modalities may exacerbate preexisting cardiac conditions. Some antineoplastic agents can adversely affect the coronary arteries, myocardium, or pericardium. It has also been recognized that cardiac damage due to radiotherapy and chemotherapy may become clinically significant many years after therapy has been completed. Treatment of urgent cardiac problems in the cancer patient may differ from that recommended for other patient groups, since many cancer patients are not ideal candidates for some of the newer cardiac agents. Management of these conditions must therefore be tailored to the individual patient.