Marine Protected Areas (MPAs) are not always placed in areas where they can maximise positive impacts on conservation and livelihoods. In other words, some reserves may be residual if placed in areas of high biodiversity where human threats are absent, or in areas of low biodiversity value. Whilst clear MPA guidelines are available that focus on biophysical criteria for maximising MPA impact, fewer considerations have been placed on incorporating socioeconomic factors into the MPA planning process. This systematic literature review identified 32 socioeconomic factors that influence whether MPA placement leads to improvements in biodiversity and/or livelihoods and weighted the quality of evidence using an “Evidence for Impact” Score. The influence of these factors varied with context. We found a generally poor evidence base for impact evaluation of socioeconomic factors, indicating the need for a more interdisciplinary approaches to MPA placement and more empirical studies that assess impact. Paper Link.