The brainstem (truncus encephali/cerebri), consisting of the medulla oblongata, pons, and mesencephalon, is one of the most vital structures of the central nervous system. Located between the brain and spinal cord, it serves as a conduit for both motor and sensory pathways, while also housing the centers for numerous life-sustaining reflexes and cranial nerve nuclei. The medulla oblongata contains centers responsible for essential autonomic functions such as respiration and cardiovascular regulation. The pons plays a critical role in motor coordination and the regulation of respiratory rhythm, serving as a bridge between the cerebrum and the cerebellum. The mesencephalon is involved in visual and auditory reflexes, motor control, and dopamine production. Cranial nerve nuclei located in all three sections provide motor and sensory innervation to the head and neck. In addition, the brainstem includes the reticular formation, which is responsible for regulating consciousness, alertness, and autonomic functions. Clinically, lesions affecting the brainstem often result in a combination of ipsilateral cranial nerve deficits and contralateral motor or sensory losses. Syndromes such as Weber, Wallenberg, and Claude arise due to vascular events or tumors, each presenting with distinct neurological findings. This study provides a comprehensive overview of the brainstem's anatomical and functional organization, detailing associated nuclei, neural pathways, and clinically significant syndromes.