We evaluated whether patients with self-reported whiplash differed in perceived pain, functional limitation and prognosis from patients with other painful neck complaints. Data from three Dutch trials and an English trial were used all evaluating conservative treatment in neck pain patients in primary care. All patients had non-specific neck pain. Information on any trauma or injury came from self-report at baseline. We compared frequencies of baseline variables and outcome at short-term and long term for whiplash and non-trauma neck pain patients separately. The total study population consisted of 804 neck pain patients. Of these patients 133 reported (16.5%) that an injury was the cause of their neck pain. In all trials there were 17-18% more male patients in the whiplash group. At follow-up pain decreased between 12 and 28%, function 10%, and 25-50% of patients recovered in all trials. Post-treatment improvements in pain, function and recovery were comparable between whiplash and non-trauma patients. We also found no different prognostic factors between whiplash and non-trauma patients. Overall we found in a population with mild to moderate pain no clinically relevant differences between patients with self-reported whiplash and patients with other painful neck complaints. The findings suggest that whiplash patients with mild to moderate pain should not be considered a specific subgroup of patients with non-specific neck pain. (C) 2011 Elsevier Ltd. All rights reserved.