Copyright © 2014 by Türki ye Klinik leri.ALCAPA syndrome is a rare anomaly that left coronary artery take origin from the pulmonary artery. Symptoms which miyocardial infarction, congestive heart failure and sudden death occur between 2 weeks and 6 months. Diagnosis can be delayed in cases of well-developed collateral circulation. 14 year-old-male patient did not have any complaints until two months ago. However, from that date his complaints of chest pain and palpitations began that they increase with long-term effort. Ventricular premature beat was seen on eletrocardiogram. In Holter rhythm recording around 2000 monomorphic ventricular premature beats were detected in 24 hours. ALCAPA syndrome was suspected on her echocardiographic examination. The diagnosis was confirmed with by catheterizasyon. Due to our patient, we wanted to emphasize the importance of echocardiographic examination in patients who present with arrhythmia.