Pathologic rupture of the spleen in hematologic malignancies is rare. We present two cases of splenic rupture which occurred in a man with a secondary high-grade non-Hodgkin's lymphoma and a woman with chronic lymphocytic leukemia (CLL). In a review of the literature, we have been able to identify 136 cases of pathologic splenic rupture since 1861; 34% have occurred in acute leukemias, 34% in non-Hodgkin's lymphomas, and 18% in chronic myelogenous leukemia (CML). We find a male-to-female ratio of 3:1, with considerable differences for the specific diseases encountered. Pathologic rupture of the spleen has happened almost exclusively in adults and the ruptured spleens are generally moderately to severely enlarged. It seems that, apart from splenic infiltration by a hematologic disease, splenic infarcts and coagulation disorders (which have previously been advanced as the most important pathophysiologic factors leading to rupture), male sex, adulthood, severe splenomegaly, and cytoreductive chemotherapy may increase the risk for pathologic splenic rupture. We briefly discuss symptoms preceding the event, diagnostic possibilities, and the outcome with operative and conservative approaches.