Four patients with systemic lupus erythematosus visiting an emergency department were reported with clinical presentation of acute pancreatitis. All had high levels of anticardiolipin antibodies (aCL); at autopsy, one had multiple thrombi within the blood vessels of the pancreas. The aCL antibody might play an important role in the pathogenesis of acute pancreatitis. Three patients had multiple organ involvement, especially the central nervous system, concomitant with an acute attack of pancreatitis; all died from these complications. Thus it was suggested that initial acute pancreatitis is an omnious prognostic factor in lupus patients visiting an emergency department. When evaluating lupus patients visiting an emergency department, clinicians should be alert to the status of aCL and the possibility of pancreatitis in these patients.