The removal of pathologically generated free radicals produced during ischemia, reperfusion and intracranical hemorrhage seems to be a viable approach to neuroprotection. However, at present, no neuroprotective agent has proven effective in focal ischemic stroke phase III trials, despite the encouraging data in animal models. This study aimed to explore the effect of the brain penetrant low molecular weight radical scavenger bis(1-hydroxy-2,2,6,6-tetramethyl-4-piperidinyl)-decandioate (IAC) in neurological damage subsequent to ischemia-reperfusion injury in Mongolian gerbils. We examined the intraperitoneal effects of IAC on temporary bilateral common carotid artery occlusion (BCCO) by means of morphological and histological analysis of the hippocampus. Significant dose-dependent protective effects of IAC (1 to 10mg/kg b.w.) against neuropathological and morphological brain changes were seen when administered i.p. 1h before temporary BCCO in Mongolian gerbils. When administered up to 6h after BCCO, IAC actually reverses the neurodegenerative processes (e.g. hippocampal cell viability) induced by ischemia in a dose-dependent fashion. Data show that IAC is highly effective in protecting and preventing oxidative brain damage associated with cerebral flow disturbances. It is also effective even in late treatment of the insult, emphasizing its potential role for the management of ischemic stroke patients.