Objective To systematically review the available evidence on the impact of organizational partnerships on public health outcomes (health improvement and/or a reduction in health inequalities) in England between 1997 and 2008. Design Systematic review of quantitative (longitudinal before and after) and qualitative studies (19972008) reporting on the health (and health inequalities) effects of public health partnerships in England. Data sources Eighteen electronic databases (medical, social science and economic), websites, bibliographies and expert contacts. Results Only 15 studies, relating to six different interventions, met the review criteria and most of these studies were not designed specifically to assess the impact of partnership working on public health outcomes. Of the studies reviewed, only four included a quantitative element and they produced a mixed picture in terms of the impacts of partnership working. Qualitative studies suggested that some partnerships increased the profile of health inequalities on local policy agendas. Both the design of partnership interventions and of the studies evaluating them meant it was difficult to assess the extent to which identifiable successes and failures were attributable to partnership working. Conclusion This systematic review suggests that there is not yet any clear evidence of the effects of public health partnerships on health outcomes. More appropriately designed and timed studies are required to establish whether, and how, partnerships are effective.