Anomalous origin of the left main coronary artery from the right sinus of valsalva is an extremely rare condition. Right-sided single coronary trunk associated with rudimentary left coronary artery is probably the rarest. The clinical significance of single coronary artery (SCA) depends on its relationship with the great arteries. The causes of myocardial ischaemia in these arteries could be impaired vasodilator response, vascular compression between great arteries or atherosclerosis. We report a 42-year-old gentleman who presented with anterior wall myocardial infarction (MI) and thrombolysed with streptokinase. The coronary angiogram done revealed anomalous right SCA (Lipton type-RII/Yamanaka RIIA) with recanalised left anterior descending artery (LAD). In this case the cause of MI could be atherosclerotic, as this patient responded to thrombolytic therapy and coronary angiogram revealed recanalised LAD. This case highlights the fact that these anomalous arteries are susceptible to atherosclerosis as are normally arising coronary arteries.