BACKGROUND: Facet joint is an important structure not only contributing to the stability of the lumbar motion segments but also causing low back pain. Hypothetically, the more lumbar lordosis decreases, the more corresponding facet joints orient axially and asymmetrically. Furthermore, the increased incidence of common diseases possessed of low back pain and radiologic findings such as wedging of vertebral body and spondylolisthesis were reported in the patients with asymmetric orientation of the facet joints and loss of lumbar lordosis at the same time. The purpose of our study is to define the relationship of asymmetry of the facet joints and loss of lumbar lordosis. METHODS: The asymmetry and average angle of facet joints with respect to sagittal plane were measured on the magnetic resonance images. The lumbar lordosis was measured on the lateral X-ray. The relevance of lumbar lordosis and facet orientation was analyzed through linear regression. RESULTS: There were no significant relationships between lumbar lordosis and asymmetrical orientation of facet joint. CONCLUSIONS: The loss of lumbar lordosis did not suggest asymmetrical and axial orientation of facet joints. Further investigation into pathology and consideration into individual differences of range of motion, body mass index, age, sex might be needed.