Electrical carotid sinus nerve stimulation was applied in three normotensive anginal patients and one hypertensive patient during upright tilting. Despite a base-line depressor response to continuous stimulation, orthostatic hypotension was not augmented. In individual patients stimulation slightly enhanced the fall of systolic pressure and delayed the increase of diastolic pressure immediately after tilting. Base-line heart rates and cardio-acceleration upon tilting remained almost uninfluenced by stimulation. It is concluded that a moderately enhanced carotid baroreceptor afferent nerve traffic did not interfere with the regular orthostatic response.