OBJECTIVE Transthoracic echocardiography (TTE) is routinely performed to look for the cardiac sources of emboli in many Western stroke centers. Due to a limitation of resources in Thailand, echocardiography is done in only some patients with acute ischemic stroke. The purpose of this study is to evaluate the need for cardiac investigations, especially TTE, in Thai patients with acute ischemic stroke. METHODS Two-hundred and seven patients with acute ischemic stroke or transient ischemic attack (TIA), who had TTE results during August 2006 to November 2008, were studied. Patients were divided into 2 groups by the risk of cardioembolism: low- versus high-risk groups. All echocardiography results were reviewed and classified by the need for management change following the echocardiography. RESULTS Abnormal TTE results indicating a need for change in management were found in 4% (4/102) and 18% (18/105) in low- and high- risk patients, respectively The results of ECG alone led to change in management in 17% (36 patients). Atrial fibrillation was the most common cause of cardioembolism, which was found in 35 patients (17%). CONCLUSIONS Because of limited resources in Thailand, ECG should be routinely performed on all ischemic stroke patients and TTE in patients with high risk for cardioembolism. However larger studies are still needed to clarify the benefits of echocardiography in low-risk patients.