The authors undertook a case-control study of chronic neck pain and whiplash injuries in nine states in the United States to determine whether whiplash injuries contributed significantly to the population of individuals with chronic neck and other spine pain.Four hundred nineteen patients and 246 controls were randomly enrolled. Patients were defined as individuals with chronic neck pain, and controls as those with chronic back pain. The two groups were surveyed for cause of chronic pain as well as demographic information. The two groups were compared using an exposure-odds ratio. Forty-five per cent of the patients attributed their pain to a motor vehicle accident. An OR of 4.0 and 2.1 was calculated for men and women, respectively.Based on the results of the present study, it reasonable to infer that a significant proportion of individuals with chronic neck pain in the general population were originally injured in a motor vehicle accident.