Objective: To systematically review evidence on the effects of timing and intensity of neurorehabilitation on the functional recovery of patients with moderate to severe traumatic brain injury (TBI) and aggregate the available evidence using meta-analytic methods. Data Sources: PubMed, Embase, PsycINFO, and Cochrane Database. Study Selection: Electronic databases were searched for prospective controlled clinical trials assessing the effect of timing or intensity of multidisciplinary neurorehabilitation programs on functional outcome of patients with moderate or severe TBI. A total of 5961 unique records were screened for relevance, of which 58 full-text articles were assessed for eligibility by 2 independent authors. Eleven articles were included for systematic review and meta-analysis. Data Extraction: Two independent authors performed data extraction and risk of bias analysis using the Cochrane Collaboration tool. Discrepancies between authors were resolved by consensus. Data Synthesis: Systematic review of a total of 6 randomized controlled trials, 1 quasi-randomized trial, and 4 controlled trials revealed consistent evidence for a beneficial effect of early onset neurorehabilitation in the trauma center and intensive neurorehabilitation in the rehabilitation facility on functional outcome compared with usual care. Meta-analytic quantification revealed a large-sized positive effect for early onset rehabilitation programs (d=1.02; P<.001; 95% confidence interval [CI], 0.56–1.47) and a medium-sized positive effect for intensive neurorehabilitation programs (d=.67; P<.001; 95% CI,.38–.97) compared with usual care. These effects were replicated based solely on studies with a low overall risk of bias. Conclusions: The available evidence indicates that early onset neurorehabilitation in the trauma center and more intensive neurorehabilitation in the rehabilitation facility promote functional recovery of patients with moderate to severe TBI compared with usual care. These findings support the integration of early onset and more intensive neurorehabilitation in the chain of care for patients with TBI.