In this paper, the influence of the orientation of intervertebral facet joints in segment L4-L5 on the development of degenerative spondylolisthesis is presented. Thirty one patients over 45 years old, who were operated because of back pain in spondyloarthrosis, were analyzed. All patients were divided into two groups. The first group consisted of the patients with degenerative spondylolisthesis at the level L4-L5. The second group consisted of the patients who were operated because of stenosis without instability at L4-L5. The significant differences in the sagittal orientation of facet joints were stated. We confirmed that the presence of more sagittaly orientated facet joints has influence on degenerative spondylolisthesis. Lack of the increase in value of this angle in patients with degenerative changes without instability allows to suppose that this process is not the result of arthritic remodeling.