BACKGROUND: Rehabilitation aims to improve hand-arm function, upper-limb strength, and functional independence that has been impaired by tetraplegia. On the basis of evidence derived from stroke rehabilitation, interventions aiming to increase intensity (i.e., duration and/or number of movements practiced) or alter brain plasticity (including motor imagery, virtual reality, transcranial direct-current or magnetic stimulations; i.e., neuromodulation) are now used during tetraplegic rehabilitation. However, no meta-analysis has investigated the efficacy of these interventions. OBJECTIVE: This systematic review and meta-analysis investigated, separately, the efficacy of these interventions to alter hand-arm function, upper-limb strength, and functional independence of individuals with tetraplegia. METHODS: Two independent reviewers followed the PROSPERO protocol (CRD42018098506) for this systematic review. MEDLINE, PEDro CENTRAL, and SCOPUS databases were searched for reports of randomized controlled trials of individuals with tetraplegia that were published in English. We performed a meta-analysis of intensive versus less intensive interventions and neuromodulation versus sham interventions considering hand-arm function, strength, and functional independence. RESULTS: From 168 records identified, we included 29 studies (all but 1 were single-centre) in the systematic review (647 participants with C2 to T1 tetraplegia [American Spinal Injury Association impairment scale A to D]). Interventions lasted from 66 to 40,320min. Five studies were retained in the intensity meta-analyses and 5 in the neuromodulation meta-analyses. Overall, 3/5 and 1/5 studies had adequate methodology (Cochrane Risk of Bias score ≥6/10). For each outcome, the p-values for the overall effect were>0.05. Heterogeneity was low, but when analyzing intensity, it was moderate for functional independence and high for hand-arm function. Quality of evidence was very low to low. CONCLUSIONS: We can provide no recommendations for using intensive versus less intensive interventions or neuromodulation versus sham during tetraplegia rehabilitation. Further multicentre studies of high methodological quality are required to reduce uncertainty about the efficacy of these interventions.