Introduction: Non-specific neck pain is a major burden to industry, yet the impact of introducing a workplace ergonomics and exercise intervention on work productivity and severity of neck pain in a population of office personnel is unknown. Research question: Does a combined workplace-based best practice ergonomic and neck exercise program reduce productivity losses and risk of developing neck pain in asymptomatic workers, or decrease severity of neck pain in symptomatic workers, compared to a best practice ergonomic and general health promotion program? Design: Prospective cluster randomised controlled trial. Participants and setting: Office personnel aged over 18 years, and who work > 30 hours/week. Intervention: Individualised best practice ergonomic intervention plus 3 20 minute weekly, progressive neck/shoulder girdle exercise group sessions for 12 weeks. Control: Individualised best practice ergonomic intervention plus 1-hour weekly health information sessions for 12 weeks. Measurements: Primary (productivity loss) and secondary (neck pain and disability, muscle performance, and quality of life) outcome measures will be collected usingvalidated scales at baseline, immediate post-intervention and 12 months after commencement. Procedure: 640 volunteering office personnel will be randomly allocated to either an intervention or control arm in work group clusters.Analysis: Analysis will be on an ‘intent-to-treat’ basis and per protocol. Multilevel, generalised linear models will be used to examine the effect of the intervention on reducing the productivity loss in dollar units (AUD), and severity of neck pain and disability. Discussion: The findings of this study will have a direct impact on policies that underpin the prevention and management of neck pain in office personnel.