60 patients with acute ischemic stroke were enrolled in a prospective single-blind, randomized trial to determine whether treatment with the calcium antagonist nimodipine would reduce their neurological deficit. All patients received a standard treatment. In addition, 29 received a daily dose of 120 mg nimodipine orally as 3 divided doses (treatment group). Evaluation of therapy was assessed with a neurological scoring system ( Mathew scale). Comparison of the Mathew sum scores in the standard group with those of the nimodipine group (analysis of variance) revealed a highly significant difference (P less than 0.0001) in favour of nimodipine during the 4 week period of treatment. Based on the individual items of the Mathew scale, the level of consciousness and disability were significantly improved under the nimodipine-therapy. Side effects were of minor importance and of no clinical relevance.