Background: Upper limb hemiplegia after stroke is common and disabling. Hand splints are widely used to prevent contracture and reduce spasticity. Objective: To assess the effectiveness of hand splinting on the hemiplegic upper extremity following stroke. Search strategy: A search was conducted of the Cochrane Central Register of Controlled Trials; the electronic databases MEDLINE, EMBASE, CINAHL, PEDro, SCI, SSCI; websites of professional associations; reference lists in trial reports and other relevant articles. Selection criteria: Studies of the effect of upper extremity splinting on motor control, functional abilities, contracture, spasticity, or pain in the hand or wrist. Data collection and analysis: Validity of studies was assessed systematically and a content analysis was conducted of the methodologies used. Methodological quality of randomized trials was rated by two independent assessors using the PEDro scale. Results: Nineteen studies were appraised for content. Of these, most (63%) were reports of case series. Four studies (21%) were randomized controlled trials. Methodological scores of trials ranged from 2 to 8 (maximum possible score 10). One trial of nominally 'medium' quality reported that inflatable arm splinting makes no difference to hand function (mean difference on Fugl-Meyer Assessment -0.12, 95% confidence interval (Cl) -9.8 to 9.6). The remaining trials investigated effects of thermoplastic splints; one trial of 'high quality' reported no difference in contracture formation in the wrist and finger flexor muscles after wearing a hand splint which positioned the wrist in the traditional functional position for 12 hours each night for four weeks (mean difference in range of movement after four weeks was 1°, 95% Cl -3.7° to 6.1°; power >80%). All remaining trials were of poor methodological quality. Limited research and lack of a no-splint control group in all trials to date limit the usefulness of these results. Reviewer's conclusion: There is insufficient evidence to either support or refute the effectiveness of hand splinting for adults following stroke.