The tolerability of four doses of intravenous nicardipine (0.03, 0.08, 0.11, and 0.15 mg/kg/h) was assessed in this randomized multicenter, parallel-group study. Fifty-two patients with Hunt and Hess grade I-III aneurysmal subarachnoid hemorrhage were treated with intravenous nicardipine beginning within 4 days of bleeding, for a mean duration of 12.6 days; this treatment was followed by administration of oral nicardipine 90-120 mg until day 30. Hypotension was the main side effect, and it occurred only in the two groups that received the highest doses. However, it was possible to continue nicardipine in all cases at lower doses or even without modification, and hypotension was never responsible for any deleterious clinical effect.