This chapter presents a systematic review of the literature that addresses the following two questions: who corporate donors are and whether corporate contributions to electoral campaigns influence policy outcomes. The material that is used in this review was obtained through a search process in the EBSCO database. In the initial search process, 436 peer-reviewed articles were identified; however, after a scrutiny process, only 40 of them reported results that are relevant to this study. This chapter offers a conceptual review of the theoretical approaches that are used by scholars and a descriptive review of the research that has been published between 2000 and 2015 that examines the two previously mentioned questions.