We studied the possible cardiovascular effects of single oral doses of 12.5, 25, and 50 mg of almotriptan, a new triptan for treatment of migraine, in a randomized, double-blind, four-way crossover, placebo-controlled study in 24 healthy volunteers aged 18 to 35 years. Doses were given at 1-week intervals. Cardiovascular effects were assessed by frequent recording of blood pressure and heart rate, 12-lead electrocardiogram (ECG) (recorded at 25 mm/s paper speed and 1 cm/mV and at 50 mm/s and 2 cm/mV), and continuous ECG monitoring for 12 h after each dose. ECG variables, PR, QRS, QT interval, and QT dispersion, were measured. QT intervals were adjusted for heart rate using Bazett's formula. None of the doses of almotriptan differed significantly from placebo with respect to PR, QRS, or QTc intervals, QTc dispersion, heart rate, or continuous ECG monitoring. Almotriptan 12.5 mg did not differ significantly from placebo with respect to systolic or diastolic blood pressure, but almotriptan 25 and 50 mg raised systolic blood pressure by a mean of 2.78 and 4.17 mm Hg, and diastolic blood pressure by 3.77 and 6.11 mm Hg, respectively, during 0 to 4 h after dosing. Thus none of the doses of almotriptan affected the ECG, and the 12.5-mg dose (the expected therapeutic dose) had no hemodynamic effects. Almotriptan in doses of 25 and 50 mg caused a small, dose-related increase in systolic and diastolic blood pressure, as seen with other triptans.