The thalamus is a vital structure lying deep within the brain that has several important functions, such as sensory and motor function, attention, memory, speech, and emotion. Various thalamic nuclei with extensive nerve networks send signals all around the structures of the brain including the cerebral cortex. Thalamic lesions cause a wide variety of clinical symptoms; therefore, anatomical knowledge of the thalamus is important in clinical situations. In this paper, structure of the thalamus is outlined, sprinkled with examples of clinical cases.