1. The intravenous administration of nicergoline (5 mg) was followed by a rapid and sustained lowering of blood pressure; less rapid effects were bradycardia and an elevation of cardiac output. These delayed effects are consistent with an indirect action on the alpha-adrenoreceptors of the central nervous system. 2. Following the oral administration of nicergoline (30 mg), a partial reduction of exercise-induced lactacidaemia was demonstrated, which is consistent with the haemodynamic changes shown at rest.