In this work the authors propose the Valsalva maneuver as a diagnostic test in a group of patients shown, by anamnestic, physical, and instrumental criteria, to be affected by vasodepressor syncope. They studied the response of heart rate and baseline arterial pressure to the maneuver performed in passive orthostasis in 7 healthy volunteers and 24 patients. These patients showed a hypotensive response and a time of recovery to the initial values that was significantly longer than in the control group (p less than 0.01). The authors conclude that studying the response to the Valsalva maneuver can be useful in the diagnosis of vasodepressor syncope.