The objective of this chapter is to introduce the nervous system. Neuroanatomy is the study of the structural aspects of the nervous system. The nervous system is made up of specialized tissue that has the special property to conduct impulses rapidly from one part of the body to another. The specialized cells that constitute the functional units of the nervous system are called neurons. The nervous system is divided into the central and peripheral nervous systems. This chapter describes neuron and classification, classification of nervous system, meninges with dural folds, ventricles and cerebrospinal fluid, brief on cerebrum, cerebellum, midbrain, pons, medulla oblongata, spinal cord with spinal/peripheral nerve (gross and histology), upper and lower motor neurons, basal nuclei, internal capsule, blood supply of brain, cranial nerves and functions, olfactory pathway, sympathetic and parasympathetic nervous system, and brief on brachial, lumbar plexus, median, radial, ulnar, femoral, obturator, sciatic, cutaneous nerve supply of dorsum of hand and foot. In this chapter, long questions are also provided.