Most of the structures in the lumbar region including the visceral organs could be the sources of low back pain. The management of low back pain starts from a thorough understanding of the anatomical structures and the underlying pathophysiologic processes related to the generation of the pain. Mechanical stresses applying to the lumbar spine and the inflammatory changes contribute to the generation of low back pain. Many nerves branching from the spinal and autonomic nerves supply all of the musculoskeletal structures in the lumbar area. There are extensive nociceptive nerve fibers in the facet joints and some small fibers in the outer layer of discs and ligaments of the lumbar vertebrae. They respond to the mechanical, chemical and other stimuli. Acute pain caused by tissue trauma or inflammation is well controlled by the removal or elimination of its causes. In idiopathic, uncontrolled and chronic pain, however, the long-lasting nociceptive stimuli and many chemical mediators released from the tissue injury and inflammation sensitize the local nervous system. They change the normal process of pain transmission to neuropathic pain. For the proper treatment of low back pain, not only the knowledge of anatomical structures but also the understanding of the pathophysiology of chronic neuropathic pain is necessary.