Background: This article aims to provide an overview of the epidemiology, medical and rehabilitation issues andrecent advances and emerging practices. We also intended to assess the validity of trials in head injury and findthe generalized concepts according to their results.Methods: All randomized controlled trials on the treatment and rehabilitation of patients with head injury publishedbefore November 2010 was surveyed. Data were extracted on the number of participants, use of blinding,loss to follow up, and types of participants, interventions, and outcome measures.Results: Until November 2010, using several search engines, 479 reports were identified. The average number ofparticipants per trial was 92. No trials were large enough to detect reliably a 5% absolute reduction in the risk ofdeath or disability. Of 226 trials assessing disability, 211 reported the number of patients followed up, and averageloss to follow up was 19%. Of trials measuring disability, 26% reported that outcome assessors were blinded.Conclusion: Randomized trials in head injury are too small and poorly designed to detect or refute reliably moderatebut clinically important benefits or hazards of treatment. Limited funding for injury research and unfamiliaritywith issues of consent may have been important obstacles.