The mechanisms for developing long-lasting neck pain after whiplash injuries are still largely unrevealed. In the present study it was investigated whether a kyphotic deformity of the cervical spine, as opposed to a straight or a lordotic spine, was associated with the symptoms at baseline, and with the prognosis one year following a whiplash injury. MRI was performed in 171 subjects about 10 d after the accident, and 104 participated in the pain recording at 1-year follow-up. It was demonstrated that postures as seen on MRI can be reliably categorized and that a straight spine is the most frequent appearance of the cervical spine in supine MRI. In relation to symptoms it was seen that a kyphotic deformity was associated with reporting the highest intensities of headache at baseline, but not with an increased risk of long-lasting neck pain or headache. In conclusion, a kyphotic deformity is not significantly associated with chronic whiplash associated pain. Moreover, it is a clear clinical implication that pain should not be ascribed to a straight spine on MRI. We suggest that future trials on cervical posture focus upon the presence of kyphotic deformity rather than just on the absence of lordosis.