This work was designed to investigate the effects of brain ischemia on mnesic retention in the model of unilateral microsphere embolization in rats. Using various radioactive tracers as well as a learning/memory test, we could correlate following parameters: regional blood flow, protein synthesis and memory retention. All were severely impaired by the hemispheric multi-infarction. A curative treatment with naftidrofuryl (15 mg/kg i.p.) for 3 consecutive days strongly improved the mnesic capacities of the animals, and this effect was corroborated by a marked protective drug action on protein synthesis in the hippocampus. Indeed, studies on valine incorporation into proteins revealed that, despite having no quantitative effect on regional blood flow, naftidrofuryl allowed an almost normal functioning of protein synthesis. As naftidrofuryl had also no direct effect on protein synthesis in the intact contralateral hemisphere, this effect was consequently attributed to the metabolic and/or antiserotoninergic effects of the drug.