Several different mechanisms contribute to the pathogenesis of cerebral vasospasm after subarachnoid haemorrhage. Whatever these mechanisms are, the vessel contraction is ultimately induced by an increase of free intracellular Ca2+ in the arterial wall. In this study, we investigated the effect on cerebral blood flow of a new dihydropyridine derivative Ca-channel blocker Niguldipine, in an rabbit experimental cerebral vasospasm model. The cerebral blood flow was significantly decreased in the saline treatment group when compared with control group. Niguldipine pretreatment caused a significant increase in cerebral blood flow. This effect should be investigated further.