Background Data: Posterior lumbar interbody fusion (PLIF) provides better stability and fusion as a surgical treatment for degenerative disc disease (DDD) and spondylolisthesis. Different cage designs are available for interbody fusion. Tantalum cages are recent and appealing options in these techniques. Purpose: To assess the clinical and radiological outcome of tantalum interbody cage in PLIF without autologous bone graft inside the cage. Study Design: A retrospective case series study. Patients and Methods: A total of 25 patients with single-level DDD (n = 16) or spondylolisthesis (n = 9) who underwent single-level PLIF surgeries with 1-year follow-up were recruited for this study. Clinical and functional assessment was done using the visual analogue scale (VAS) for low back pain and Oswestry Disability Index (ODI). Tantalum cage stability and fusion were assessed radiologically on static and dynamic lateral X-ray. Results: VAS and ODI showed significant postoperative improvement at 6-week and 3-, 6-, and 12-month follow-up intervals. No significant migration or subsidence of tantalum cage was reported on static X-ray, no significant mobility was reported on dynamic X-ray, and the total sound bone fusion rate was 96% at 1-year follow-up. Conclusion: Our data suggest that PLIF with tantalum interbody cage in lumbar DDD and low-grade spondylolisthesis showed good clinical and functional results in 1-year follow-up with high spinal stability and bone fusion rate (2020ESJ225).