This review was conducted to find out whether OHS training has a beneficial effect on workers and firms, and whether higher engagement OHS training is more beneficial than lower engagement OHS training. The systematic review team consisted of 16 researchers from the United States and Canada. The review team searched 10 electronic databases for studies of randomized controlled trials published on OHS education or training between 1996-2007. An initial 6,469 articles were identified and reviewed for relevance.