The English literature on the incidence of nystagmus in normal subjects and in patients with head and/or neck injuries is reviewed. The authors present a series of 202 patients with alleged vestibular trauma. The incidence of spontaneous and positional nystagmus would seem to be no greater in patients with alleged vestibular trauma than that found in the normal subjects, suggesting that these patients do not have objective evidence of vestibular trauma. Objective criteria for diagnosing vestibular abnormalities by electronystagmography are presented. At least 22% of a series of 2408 patients were found to have a functional hearing loss. The importance of looking for functional overlay in patients involved in litigation cases is stressed.