Posterior longitudinal ligament ossification (PLLO) is a hyperostotic condition that results in ectopic calcification of the posterior longitudinal ligament, resulting in decreased spinal range of motion and potentially leading to spinal cord damage. Although it is still unclear how PLLO begins and progresses, studies show the existence of predisposing factors such as genetic, hormonal, environmental, nutritional characteristics, mechanical stress, and some systemic diseases. It is affected by epidemiology, geographical location and ethnicity, and is common in East Asian countries. Symptoms may vary in a wide spectrum depending on severity, duration and involvement characteristics. Cervical myelopathy and cervical radiculopathy, axial discomfort around the neck and limitation of neck movement are the main symptoms. Physical examination may also reveal findings of myelopathy, radiculopathy and axial involvement. In addition to cervical imaging methods, myelography, metabolic examination and electrodiagnosis are helpful tools in diagnosis. Cases where myelopathy is absent or subclinical are suitable for conservative treatment. Surgical decompression is indicated in patients with long tract symptoms such as spastic gait disturbance and clumsiness of the hands. Although the most appropriate surgical method is controversial, two basic surgical approaches are accepted: the anterior procedure, which is performed by removing or floating the ossified lesion, or the posterior procedure, which includes various types of expansive laminoplasty.