We performed a prospective study of patients with a whiplash trauma to the cervical spine to describe the incidence of these injuries and to evaluate prognostic factors for disability and recovery. A total of 356 patients were enrolled in the study. All the patients received a comprehensive questionnaire after the injury, and 296 cases responded to the follow-up protocol more than 1 year after the accident. Disability related to the whiplash trauma was used as the outcome variable for the assessment of prognostic factors. The annual incidence of acute whiplash trauma in the catchment area was 4.2 per 1,000 inhabitants and 3.2 per 1,000 for whiplash-associated disorder grades 1–3. Thirty-two percent reported persisting disability at follow-up. The following factors were significantly associated with a poor prognosis: pretraumatic neck pain, low educational level, female gender, and whiplash-associated disorder grades 2–3.