Taurine, an abundant amino acid in the nervous system, is reported to reduce ischemic brain injury in a dose-dependent manner. This study was designed to investigate whether taurine protected the brain against closed head injury (CHI) in rats. Taurine was administered intravenously 30 min after CHI. It was found that taurine lessened body-weight loss and improved neurological functions at 7 days after CHI. Moreover, it lowered brain edema and blood-brain barrier permeability, enhanced activity of superoxide dismutase and the level of glutathione, and reduced levels of malondialdehyde and lactic acid in traumatic tissue 24 h after CHI. In addition, it attenuated neuronal cell death in hippocampal CA1 and CA3 subfields 7 days after CHI. All of these effects were dose dependent. These data demonstrated the dose-dependent protection of taurine against experimental CHI and suggest that taurine treatment might be beneficial in reducing trauma-induced oxidative damage to the brain, thus showing the potential for clinical implications.