BACKGROUND: The most widely adopted materials for interbody fusion implants are titanium and polyetheretherketone (PEEK), both of which have potential advantages and disadvantages. Despite the differences between PEEK and titanium, there is no consensus on which material provides better clinical and radiological outcomes. Therefore, the purpose of this meta-analysis was to analyze the clinical and radiographic outcomes between the 2 cages. METHODS: Four databases (PubMed, Cochrane, Embase, and Google Scholar) were queried since December 2001 up until December 2023. Clinical outcomes evaluated included rates of adverse events, radiographic outcomes, and patient-related outcomes. RESULTS: Higher rates of subsidence and revision were reported in PEEK cages in the lumbar spine (P = 0.0006 and P = 0.006, respectively). In the cervical spine, no difference was observed between PEEK and titanium in any analysis. CONCLUSIONS: In the lumbar spine, titanium cages were shown to have a lower rate of subsidence and revision compared with PEEK cages. In the cervical spine, the difference between cages did not reach statistical significance in any of the analyzed outcomes.