The basic condition for good visualization of ventricular structures is ventricular dilatation. Although currently it is possible to perform endoscopic procedures with non-dilated ventricles by neuronavigation techniques [1, 2], the vast majority of procedures are performed with dilated ventricles. Rigid endoscopy systems have a much higher image quality when compared with flexible systems. All pictures presented here were obtained from Karl Storz rigid endoscopy Gaab (6° viewing angle) systems and Oi HandyPro (0° viewing angle) (Karl Storz, Tuttlingen, Germany). The entry point used was Kocher’s point , in most cases on the right side, a point from which it is possible to perform the majority of ventricular procedures. This hole is located about 2 cm anterior to the coronal suture and 2 cm lateral to the midline, approximately at the mid-pupillary line [3, 4]. Depending on the condition being treated, these coordinates may vary by centimeters. After entering the lateral ventricle (Figs. 3.1, 3.2, 3.3, 3.4, and 3.5), the first significant anatomical viewing is the foramen of Monro, the gateway to the third ventricle. An important topographic detail is that the choroid plexus always lies in the posterior margin of the foramen, in close contact with the angle formed by the superior thalamostriate vein and the anterior septal vein [3] (Fig. 3.6). In certain cases a foraminoplasty may be necessary, making use of a Fogarty balloon catheter. Although this procedure is controversial, it can be performed safely and without permanent memory deficit if the structures in this region are properly displayed [5, 6, 7]. The foramen may still be occluded by arachnoid cysts within the lateral ventricles (which are basically treated with fenestrations to reduce their volume [8, 9]), or by tumors such as colloid cysts, which can be completely resected by neuroendoscopy [10]. Other procedures to be performed in this region are septostomy for an isolated lateral ventricle [7], and choroid plexus coagulation, as discussed in Part I. The initial endoscopic viewing angle shown in Fig. 3.7 is intended for visualization of the structures in the body of the lateral ventricle (see Figs. 3.8, 3.9, 3.10, 3.11, 3.12, 3.13, 3.14, 3.15, 3.16, 3.17, 3.18, 3.19, 3.20, 3.21, 3.22, 3.23, 3.24, 3.25, 3.26, 3.27, 3.28, 3.29, 3.30, 3.31, 3.32, 3.33, 3.34, 3.35, 3.36, 3.37, 3.38, 3.39, 3.40, 3.41, 3.42, 3.43, 3.44, 3.45, 3.46, 3.47, 3.48, 3.49, 3.50, 3.51, 3.52, and 3.53). The endoscopic viewing angles for better visualization of the septum pellucidum (Fig. 3.54), frontal horn (Fig. 3.75), and atrium (Fig. 3.80) are shown prior to the following figures in each region (Fig. 3.55, 3.56, 3.57, 3.58, 3.59, 3.60, 3.61, 3.62, 3.63, 3.64, 3.65, 3.66, 3.67, 3.68, 3.69, 3.70, 3.71, 3.72, 3.73, 3.74, 3.76, 3.77, 3.78, 3.79, 3.81, 3.82, 3.83, 3.84, 3.85, 3.86, 3.87, 3.88, and 3.89). Illustrative cases are presented.