Anomalous origin of the left coronary artery from the pulmonary artery (ALCAPA) is a rare congenital malformation. It is unusual for an ALCAPA patient to survive to adulthood. We present a case of an asymptomatic 54-year-old woman with this syndrome in which visualization of a markedly enlarged and tortuous right coronary artery and intercoronary collaterals by echocardiography raises suspicion for this disease and subsequently guides a step-by-step diagnosis. The patient lives well without surgery 3 years after diagnosis.