Two recent cases of splenic infarction of unusual cause stimulated a review of our experience with this condition. We conducted a retrospective chart review of selected patients with pathologic diagnosis of splenic infarction seen at a large metropolitan private teaching hospital during the past 30 years. Variables analyzed included sex, age, etiology of infarction, underlying diseases, diagnostic tests, splenic pathology, and complications. Splenic infarction occurred in 59 patients (33 male and 26 female; average age, 55 years; range, 2-87 years). Etiologies included hematologic disorders (n = 35), thromboembolic disorders (n = 17), and other diseases (n = 7). Symptoms were present in 69 per cent of the patients and included abdominal pain, fever and chills, and constitutional symptoms; 18 patients were asymptomatic. Patients with nonmalignant hematologic conditions were often asymptomatic (55%); abdominal pain was common in all groups, and fever was especially common in patients with embolic conditions (70%). CT scan was the most frequent radiologic study. Patients with hematologic conditions usually were explored for complications of those conditions (69%), while complications of splenic infarction were a frequent indication for operation in patients with emboli (60%). Overall morbidity was 36 per cent, with pulmonary complications most frequent, and mortality was 5 per cent. We conclude that splenic infarction must be suspected in patients with known hematologic or thromboembolic conditions who develop left upper quadrant pain and signs of localized or systemic inflammation. CT scan is currently the preferred diagnostic test, but ultimate diagnosis depends on pathologic examination of the spleen. Surgical complications of splenic infarction include abscess and rupture.