The purpose of this study was to reveal the computer-aided three-dimensional (3D) appearance, the dimensions, and neighbourly relations of the claustrum and make a stereotactic approach to it by using serial sections taken from the brain of a human cadaver. The Snake technique was used to carry out 3D reconstructions of the claustra and surrounding structures. The photorealistic imaging and stereotactic approach were rendered by using the Advanced Render Module in Cinema 4D software. The claustrum takes the form of the concavity of the insular cortex and the convexity of the putamen. The inferior border of the claustrum is at about the same level as the bottom edge of the insular cortex and the putamen, but the superior border of the claustrum is at a lower level than the upper edge of the insular cortex and the putamen. The volume of the right claustrum, in the dimensions of 35.5710 mm x 1.0912 mm x 16.0000 mm, was 828.8346 mm³, and the volume of the left claustrum, in the dimensions of 32.9558 mm x 0.8321 mm x x 19.0000 mm, was 705.8160 mm³. The surface areas of the right and left claustra were calculated to be 1551.149697 mm2 and 1439.156450 mm² by using Surfdriver software. This is the first study reporting the 3D reconstruction and photorealistic imaging of the claustrum of the human brain. This technique enables us to determine the spatial coordinates of the target tissues and to rehearse the surgical procedures for preoperative trajectory planning by using virtual surgery. We believe that this study will be a really useful anatomic guide for neuroscientists and neurosurgeons interested in the claustrum. (Folia Morphol 2011; 70, 4: 228–234)