Intraoperative ultrasound (IOUS) is a reliable solution to obtain a real-time visual feedback that can influence surgical planning and decision-making. Today, IOUS is not commonly used in neurosurgery, mainly because US is not a diagnostic tool for central nervous system pathologies, with subsequent lack in brain and spinal US semeiotics and topographic anatomy. Most neurosurgeons are accustomed to the panoramic view of MRI and CT on the traditional orthogonal planes (coronal, sagittal and axial) while IOUS provides an unusual sectorial tomographic representation with a specific semeiotics. Moreover, IOUS requires a specific training on the proper parameters and settings to achieve a satisfactory imaging quality. In this chapter we will try to standardize the intraoperative exam along with the main semeiotics findings in neurosurgery.