Splenic and renal infarctions are common manifestations of cardiac thromboembolism. Usually they remain clinically silent and are not likely to be diagnosed antemortem. Two elderly female patients, in whom nonrheumatic chronic atrial fibrillation was noted, received low-dose aspirin. Both complained of the onset of acute abdominal pain and were found to have splenic and renal infarctions on abdominal computerized tomography. An enlarged left atrium was seen on echocardiogram in both cases. Treatment consisted of hydration, analgesics, and anticoagulation. In one case, liquefactive necrosis of the splenic infarct was observed on subsequent computer tomography studies. Both patients did well and remained free of new embolic events in the following 6 and 10 months, respectively. Clinicians should readily recognize the clinical manifestations of splenic and renal infarctions in patients with atrial fibrillation. Abdominal computerized tomography can confirm the diagnosis.