Three hundred and nine patients, whose chief complaint was dizziness following a flexion-extension type of acceleration neck injury, were examined in the Neurosensory Laboratory of Temple University Health Sciences Center between 1965 and 1972. Specific attention was devoted to vestibular tests, including a search for latent and positional nystagmus, bithermal calorics, and rotatory tests. All tests were performed with the aid of electronystagmography; latent nystagmus was present in 29 percent of the patients, caloric tests were abnormal in 57 percent, and rotatory tests were abnormal in 51 percent. These findings suggest that many of these patients have a verifiable objective vestibular disturbance as a cause of dizziness, even though the neurologic examination may be normal. Furthermore, in order to detect this objective vestibular dysfunction, the patient should be tested with aid of electronystagmography since nystagmus may be inhibited by visual fixation.