A man in his early 50s presented to the emergency department (ED) with sudden onset of palpitation and presyncope. The 12-lead electrocardiogram (ECG) recorded in ED showed monomorphic ventricular tachycardia requiring cardioversion in view of haemodynamic instability. The patient was subsequently detected to have an anomalous left coronary artery origin from the pulmonary artery. We present the features of this case that lead to clinical suspicion of this disease and discuss the presentation of anomalous left coronary artery origin from the pulmonary artery (ALCAPA) in adults.