Introduction. The aim of this study was the development of a simple galvanic stimulator for routine clinical use, which by stimulation of the vestibular nerve helps to discriminate between labyrinthine and retro-labyrinthine lesions, as well as to localise the side (left–right) of the retro-labyrinthine function loss. Patients and methods. By way of retro-auricular electrodes 13 healthy controls and 49 patients with vestibular complaints (with and without caloric hyporeflexia) were stimulated unilaterally and bilaterally with the use of a computer-assisted stimulator. The platform on which the subject was standing recorded the body sway. Also the tendency to fall with the use of a simple battery stimulator (9V) without platform was observed. Results. Patients were more instable at rest than controls. During stimulation a significant instability increase was seen. In the patient group bilateral stimulation increases instability more than unilateral stimulation. At caloric areflexia with an intact vestibular nerve a galvanic response could be evoked. Stimulation with the battery stimulator gave comparable results. Conclusion. Galvanic stimulation by use of the simple battery driven stimulator increases the body instability and gives additional information about the function of the vestibular nerve when there is complete caloric areflexia.