In order to assess the long-term efficacy of a multi-modal rehabilitation approach on whiplash injury, 60 patients were recruited within two months after neck injury. They were randomly allocated either to an experimental multimodal treatment (A) consisting of postural training, manual technique and psychological support or to a control treatment (B), using physical agents only, such as electrical and sonic modalities. Pain level, range of movement, self-rating scale of treatment efficacy and return-to-work delay were evaluated before and at the end of treatment, and later, 30 and 180 days after randomisation. The benefit obtained with treatment "A" was greater and longer lasting than that experienced using "B", despite the fact that the same benefit was obtained in joint mobility in the two groups. Patients undergoing the experimental treatment returned to their usual occupations sooner than the controls. The results seem to confirm the hypothesis of a multifactorial involvement as a possible mechanism for the late whiplash syndrome.