Image guidance in pituitary surgery has evolved since diagnostic imaging of the sellar region was first introduced at the turn of the 20th century. These advances have played a key role in the decrease in morbidity and mortality once associated with pituitary surgery. This chapter details the history of sellar imaging as a preoperative diagnostic aide, and then examines the subsequent development of image guidance systems and intraoperative imaging. The utility and limitations of common intraoperative aides including video fluoroscopy, frameless stereotaxy, ultrasound, and magnetic resonance imaging are reviewed.