In patients with traumatic spinal cord injury (tSCI) a distinction in surgical urgency is made on the basis of the severity of the initial neurological injury. The optimal timing of surgical decompression, as well as its impact on neurological recovery, is as of yet undetermined. This study addresses neurological improvement after early and late surgery for complete and incomplete cervical tSCI. A systematic search retrieved 15 publications of observational studies reporting outcome measurements after surgery in 1126 patients with cervical tSCI from PubMed and Embase databases. Surgery was considered early within 24 h, and late thereafter. An improvement of at least two grades on the American Spinal Injury Association (ASIA) scale was considered clinically meaningful. The Meta-analysis of Observational Studies in Epidemiology (MOOSE) guidelines were followed. Improvement rates were summarized using individual patient data in a Bayesian random effects model and compared for those with complete and incomplete tSCI after early and late surgery. In patients with complete cervical tSCI (n = 422), improvement was more frequent after early surgery than after late surgery (respectively, 22.6%, 95% credibility interval [CI]: 16.6-28.7% and 10.4%, 95% CI: 5.6-15.8%; odds ratio [OR] 2.6 [95% CI: 1.4-5.1]). Whereas in patients with incomplete cervical tSCI (n = 636), improvement was similar between early and late surgery (respectively 30.4%, 95% CI: 19.8-41.6% and 32.5%, 95% CI: 21.4-45.8%; OR 0.9 [95% CI: 0.4-1.9]). These data suggest a paradigm shift in the treatment of patients with complete cervical tSCI, as surgical decompression within 24 h is more frequently associated with clinically meaningful improvement. In incomplete cervical tSCI, neurological outcome is similar between early and late surgery.