The objective of this study was to analyze echocardiographic characteristics of anomalous origin of the left coronary artery from the pulmonary artery (ALCAPA) and to explore the diagnostic value of transthoracic echocardiography. The echocardiographic characteristics of 8 patients hospitalized with ALCAPA from 2000 to 2005 were analyzed retrospectively, including the results of real time three-dimensional echocardiography in one case, and compared with angiographic results. Eight cases included 6 older type patients and 2 infant type patients. Echocardiography showed abnormal vessel inserting into pulmonary artery (PA), continuous shunt into PA and intercoronary collateral signals within the ventricular septum in all cases and bifurcate structure of the abnormal vessel with retrograde filling in 4 cases. The morphological and functional changes and valvular regurgitation induced by insufficient myocardial perfusion were also evaluated. In former 4 patients, 2 cases were misdiagnosed as right coronary artery-PA fistula and the other 2 cases were given an uncertain diagnosis of anomalous origin of the coronary artery because of the visualization of the echo-free linear structure which apparently arose from the aorta resembling a normal left coronary artery. The latter 4 patients were correctly diagnosed by excluding the aforementioned interference. The diagnosis of ALCAPA was confirmed by angiocardiography in all patients and by intraoperative findings in 4 patients. Based on the apprehension of ultrasonic features and the enhancement of diagnostic alertness, the echocardiography can evaluate ALCAPA accurately and give more information than angiography. It may be the first diagnostic choice.