OBJECTIVE: To compare two different home exercise programmes for patients with acute whiplash-associated disorders (WAD). A further aim was to describe the initial prognostic variables related to self-reported pain at six months follow-up. DESIGN: A randomized treatment study with a follow-up period of six months. SETTINGS: The study was undertaken in an orthopaedic clinic at a university hospital. SUBJECTS: A total of 59 symptomatic (neck pain, stiffness, etc.) patients with acute whiplash injury. INTERVENTIONS: Patients were randomized to a regular treatment group (RT group) and an additional-exercise treatment group (AT group). MAIN OUTCOME MEASURES: Pain Disability Index (PDI), Self-Efficacy Scale (SES), Coping Strategies Questionnaire (CSQ), neck range of motion (ROM), head posture, kinaesthetic sensibility, visual analogue scale (VAS). RESULTS: Patients given an additional exercise did not improve more than patients with regular treatment. Only one CSQ item, 'Ability to decrease pain', showed a significant difference between the groups in its pattern of change over time: the AT group had a significant increase between three and six months whilst values in the RT group decreased. Nonsymptomatic patients at six months follow-up were characterized by initially better self-efficacy, lower disability and significantly different patterns in the use of 'behavioural coping strategies' when compared with symptomatic patients. The nonsymptomatic patients also reported more frequent training than symptomatic patients, i.e. they complied better with the treatment regime. CONCLUSION: This home exercise programme, including training of neck and shoulder ROM, relaxation and general advice seems to be sufficient treatment for acute WAD patients when used on a daily basis. Additionally, patients reporting low self-efficacy and high disability levels may profit from more attention initially, as these psychological factors are significant predictors of pain at long-term follow-up.