The insula is not visible on the surface of the hemisphere, as it is totally covered by the frontoparietal and temporal opercula. It has a triangular shape and is separated from the opercula by the anterior, superior, and inferior periinsular sulci. The insula is morphologically divided into two parts by the central insular sulcus. The anterior part of the insula bears three gyri—the anterior, middle, and posterior short insular gyri—separated by the anterior and precentral insular sulcus. The posterior part of the insula contains the anterior and posterior long insular gyri, separated by the postcentral insular sulcus. The vascular supply of the insula is mainly provided by the M2 and M3 segments of the middle cerebral artery. Histologically, the insula is a part of the paralimbic cortex, as it bears in its anteroinferior part an allo (agranular) and meso (dysgranular) cortical area, in addition to the more posterosuperior iso (granular) cortex. The insula is functionally involved in visceromotor, viscerosensory, autonomic, language, gustatory, and auditory functions, and there are numerous evidences of its involvement as a somesthetic area, including a major role in the processing of the nociceptive inputs. Surgery of the insular lobe is a technical challenge, whose risks can be minimized by the knowledge of its anatomical features.