To determine the impact of echocardiography in management of patients with systemic embolism, we retrospectively reviewed medical records and echocardiograms of 191 consecutive patients with suspected systemic embolism. One hundred sixteen patients had two dimensional echocardiograms and 75 patients had M-mode echocardiograms only. Patients were divided into three groups: Group 1 had no cardiovascular disease; Group 2 had cardiovascular disease, and Group 3 had hypertension only. Changes in therapy following echocardiogram were defined as initiation or discontinuation of anticoagulants or antiplatelet agents, cardioversion, or surgical intervention. M-mode echocardiogram did not identify any heart as a likely source of systemic embolism. Two dimensional echocardiogram defined 13 hearts as likely sources of emboli. All of these patients had known cardiovascular disease. Four of 13 patients (30.7%) whose hearts were likely sources of emboli had a change in therapy compared with 42 of 126 patients (33.3%) with low probability echocardiograms. We conclude that M-mode echocardiogram has no role in evaluation of patients with systemic emboli. Two dimensional echocardiogram may identify the heart as a source of emboli in patients with cardiovascular disease but does not alter early management.