This chapter describes peripheral nerves and skeletal muscles. Main components of peripheral nerves are axons and myelin sheaths made by Schwann cells. Axonal neuropathies, anatomic patterns of peripheral neuropathies, and specific peripheral neuropathies are the general types of peripheral nerve injury. Skeletal muscle atrophy, inflammatory myopathies, toxic myopathies, and inherited diseases of skeletal muscle are different types of diseases of skeletal muscle. Atrophy of skeletal muscle is a common feature of many disorders. These include loss of innervation, disuse, cachexia, old age, and primary myopathies. Loss of muscle mass is found in severe atrophy. At the end of this chapter, self-assessment exercise is also provided, which are helpful for better preparation.