Five cases of pathologic rupture of the spleen in patients with hematologic malignancy are presented along with a review of the 48 cases previously described in the English literature. Pathologic splenic rupture occurred most commonly in patients with acute leukemia but has been well documented in chronic leukemias and in lymphoma as well. Nearly all patients experience abdominal pain at the time of rupture; however, this pain was frequently confused clinically with that of biliary tract obstruction, aortic aneurysm, perforated viscus, pancreatitis, and angina pectoris. Pain referred to the left shoulder (Kehr's sign) was present in only 17% of patients. Hypotension was documented in 66%, fever in 74%, and tachycardia in 75%. The most effective diagnostic procedure was paracentesis, which confirmed intraabdominal hemorrhage in each of the nine cases in which the procedure was used. A correct preoperative diagnosis of splenic rupture was reported in only 10 of the 53 cases reviewed. Fifty-two percent of the patients underwent laparotomy; 48% died without operation. Of those that underwent surgery, 78% survived the procedure and the immediate postoperative period. The survival rate of all patients was 38%. There was no correlation of the type of hematologic malignancy, occurrence or type of treatment, peripheral blood counts, or spleen size to survival. The most important factor in predicting survival was appropriate surgery.