The prevalence of knee osteoarthritis (OA) is rising and the search for interventions to mitigate risk is intensifying. This review considers the contribution of occupational activities to disease occurrence and the lessons for prevention.Systematic search in Embase and Medline covering the period 1996 to November 2011.Reasonably good evidence exists that physical work activities (especially kneeling, squatting, lifting and climbing) can cause and/or aggravate knee OA. These exposures should be reduced where possible. Obese workers with such exposures are at additional risk of knee OA and should therefore particularly be encouraged to lose weight. AREAS OF UNCERTAINTY/RESEARCH NEED: Workplace interventions and policies to prevent knee OA have seldom been evaluated. Moreover, their implementation can be problematic. However, the need for research to optimize the design of work in relation to knee OA is pressing, given population trends towards extended working life.