A patient with a giant fusiform aneurysm of the left inferior trunkus of the middle cerebral artery (MCA) is presented. The size of the aneurysm was 5 cm at its largest diameter. Retrograde flow was well developed. After the application of temporary clips the aneurysm was excised and microsurgical reconstructions were undertaken. Adequate flow in the reconstructed MCA trunkus was maintained. This rare case is discussed in the light of the literature.