Although several risk factors have been reported for cervical ossification of the longitudinal ligament (opLL), most evaluations made in the past were based on plain X-ray, not on computed tomography (ct) scan. in this study, we aimed to clarify novel risk factors for cervical opLL in asymptomatic subjects undergoing CT scan as their routine medical checkups. A total of 1789 Japanese asymptomatic subjects who underwent ct scan for the whole body as their routine medical checkups were retrospectively reviewed. the medical checkup also included laboratory examinations, bone mineral status, and ultrasound of the carotid artery. As a result, cervical OPLL was seen in 120 subjects (6.7%). As we compared the demographic and clinical data between subjects with and without opLL, opLL group showed older age, higher proportion of male sex, higher BMi, higher incidence of hypertension, higher levels of blood HbA1c and triglyceride, and higher incidence of plaques in the carotid artery. A multivariate logistic regression analysis revealed that age (Odds ratio (OR):1.03), male sex (OR: 1.91), and the presence of plaque in the carotid artery (OR: 1.71) were risk factors for OPLL. To the best of our knowledge, this is the first report to reveal an association between OPLL and arteriosclerotic lesions. Ossification of the posterior longitudinal ligament (OPLL) is a disorder characterized by progressive ectopic OPLL. Although the precise mechanisms of OPLL remain uncertain, it is considered a multifactorial disease with both environmental and genetic factors; in addition, several risk factors have been reported, including age, male sex, ethnicity, presence of diabetes mellitus, obesity, diet, sleeping time, and mechanical stimulation 1-9. Most OPLL patients are diagnosed by X-ray or computed tomography (CT) scanning when they present with radiculopathy or myelopathy. When symptoms are severe with evidence of compression to the nerve root or spinal cord, surgical intervention is often required. However, past epidemiological studies revealed that the incidence of OPLL may be higher in the general population because some patients do not present with clinical symptoms regardless of the presence of OPLL 4,10. Most epidemiological studies of OPLL have used X-rays for diagnosis; importantly, CT scans can provide more accurate diagnoses of OPLL than X-rays. There has been one study comparing the incidence of OPLL among various ethnic groups by using CT scans 11 ; however, there have been no previous reports regarding risk factors of OPLL based on diagnosis through CT scans. In this study, we aimed to investigate novel risk factors for cervical OPLL in asymptomatic subjects undergoing their routine medical checkups, which included laboratory examinations, bone mineral status evaluation, carotid artery ultrasound, and whole-body CT scans. To the best of our knowledge, this is the first study to assess the association between OPLL and arteriosclerosis.