A rare case of partially thrombosed giant serpentine right middle cerebral artery aneurysm presented. A 26 year old man initially presented with headache and 3 months later developed neurological deficit. Various stages of clot with patent residual lumen seen on neuroimaging, led to the diagnosis. Catheter angiography is the investigation of choice for evaluating the location, flow dynamics and extent of the serpentine aneurysm. The patient had embolisation done for the giant serpentine aneurysm.