Today there is increasing recognition amongst philanthropists, charity leaders and policy makers, that in order to be effective, the process of giving resources needs to be grounded in evidence. However, it is often suggested that there is insufficient evidence upon which philanthropists can rely, in part because \u2018good quality data on successful interventions is still not widely published\u2019 (Kassatly, 2018 p.1). This review aims to identify limiting and promoting factors regarding the use of evidence by philanthropists and to evaluate and synthesise existing research on this issue. This will include: Primary research or systematic reviews investigating the perceptions and\/or experiences of philanthropists relating to their use of evidence. Studies investigating the perceptions of professionals (such as charity CEO\u2019s; philanthropic advisors and philanthropic consultants) as to how evidence is used by philanthropists. All study designs will be eligible for inclusion provided they examine factors affecting the use of evidence by philanthropists however, such factors need not be the primary focus of those studies. Anticipated findings relating to barriers include: insufficient time and resources to uncover relevant information; insufficient robust evidence; and a lack of trust in the sources of the information. Expected facilitators of the use of evidence include: peer recommendations; conferences and philanthropy clubs or intermediaries.