Purpose: We aimed to research in detail the morphology of the facet orientation (FO) and tropism (FT) in degenerative diseases. Method: This study consisted of patients with disc degeneration (DD) and with lumbar spondylolisthesis (LS) as well as a control group without these two diseases. The group of patients with DD was separated by DD grades. Vertebral body and intervertebral discs’ (IVDs) morphometric values, facet joint osteoarthritis (OA) grading, FO and FT were examined in all the groups. All measurements were applied to MRIs of 353 patients. Result: There was a significant difference in facet angle values between the groups at L4–L5 (FO: p = 0.001). There was a significant negative correlation between FO at L4–L5 and L4 vertebral body anterior posterior diameter and L5 mid-vertebral body height, in 353 patients (p = 0.003; p = 0.010). Facet joint OA grading scores were lower in the control group than in the disc degeneration patient (DDP) and LS groups (p < 0.05). Sagittal FO was seen with the increase of facet joint OA scores at L4–L5 in the control and DDP groups (control: p = 0.001; DDP: p = 0.40). Conclusion: Facet joints can show different orientation values in LS and DDP groups at L4–L5. The presence of FT is a risk factor for an LS patient at L4–L5. Sagittal FO is seen with vertebral slip at L5–S1. FO is affected by the morphometric changes of the vertebral body at L4–L5. Discussions in this regard need to be resolved through further research.