The sacrotuberous ligament is a slender, fan-shaped ligament of the posterior pelvis located on either side of the body. This ligament arises midway down the posterior side of the sacrum, which is located at the spinal base. It primarily comprises of collagen fibers, and is strong enough to support the sacrum and prevent it against moving from its position under the body weight. The connective tissue in this ligament joins with various other tissues, particularly the biceps femoris muscular tendon, which is an important muscle of the hamstrings on the posterior thigh region. It is also a ligament of the sacroiliac joint, which is connected to the sacrum. It typically receives stress during aggressive physical activities and sports that may cause the arching of the spine. If it becomes strained or injured, it may result in problems similar to those of a typical iliolumbar ligament injury. The ossified or bony sacrotuberous ligament may be one of the critical causative factors in different types of neurovascular compression syndromes. An anatomical understanding of this ligament may lead to effective treatments for this clinical disease.