The lumbar spine is of critical importance in neurosurgery, as lumbar degenerative disease is among the leading causes of disability worldwide. Given its central role in both weight-bearing and movement, the lumbar spine is frequently affected by mechanical stress, leading to degenerative conditions. A thorough understanding of lumbar anatomy is fundamental to diagnosing and treating these conditions. This chapter provides a detailed review of lumbar anatomy, focusing on clinically relevant bony, vascular, neural, and ligamentous structures that are commonly implicated in disease processes.