Pericardial involvement, a rare complication of multiple myeloma (MM), is caused by amyloidosis, infections, bleeding abnormalities or plasma cell infiltration, usually at a late or terminal stage of the disease. Three cases of MM with pericardial involvement are reported here and discussed in the light of current literature. In a retrospective review of all patients with MM at two institutions, three cases of pericardial involvement were identified. In one case, we were able to obtain cytospin preparations of the pericardiocentesis fluid. In the remaining two patients, the pericardial biopsy specimen was obtained via a pericardial window. All patients had progressive dyspnea and signs of pericardial tamponade. The pericardiocentesis fluid showed infiltration with plasma cells in one of the three patients, who had a progressive and fatal course. In the second patient pericardial invasion was proven by biopsy and the third was diagnosed with a plasma cell leukemia but developed a pericardial effusion demonstrated by pericardial biopsy. All these three patients died of progressive disease without any response to chemotherapy and supportive measures. In conclusion, optimal treatment for malignant involvement of the pericardium by myeloma cells has not yet been established and is often fatal.