Coronary artery aneurysms are exceedingly rare and tend to be found incidentally on angiography. We present the case of a 6cm giant coronary artery aneurysm discovered in a 25 year old man. Subsequent workup included cardiac gated MRI, CT angiography and left heart catheterization. Imaging revealed a 6.7 x 6.2 x 6.0 cm aneurysm involving the mid LAD subsequent to the takeoff of a large septal perforator. He was taken electively for operative repair during which the aneurysm was opened, unroofed and ligated at the ostium while taking care to ensuring normal flow in the septal perforator that supplied multiple small collaterals. In this unique case, a coronary artery aneurysm of considerable size was encountered in the LAD of a healthy young adult in which the size of the aneurysm precluded distal revascularization via bypass grafting. Multiple imaging modalities were used to characterize this finding and aid in surgical planning.