OBJECTIVE: To map the health effects of interventions which aim to alter the psychosocial work environment, with a particular focus on differential impacts by socio-economic status, gender, ethnicity, or age. METHODS: A systematic approach was used to identify, appraise and summarise existing systematic reviews (umbrella review) that examined the health effects of changes to the psychosocial work environment. Electronic databases, websites, and bibliographies, were searched from 2000-2007. Experts were also contacted. Identified reviews were critically appraised and the results summarised taking into account methodological quality. The review was conducted in the UK between October 2006 and December 2007. RESULTS: Seven systematic reviews were identified. Changes to the psychosocial work environment were found to have important and generally beneficial effects on health. Importantly, five reviews suggested that organisational level psychosocial workplace interventions may have the potential to reduce health inequalities amongst employees. CONCLUSION: Policy makers should consider organisational level changes to the psychosocial work environment when seeking to improve the health of the working age population.