ABSTRACT Understanding the effects of persuasive message repetition and the related concept of message fatigue is uniquely relevant to the field of communication, and an account of the state of theory and research in the field can be provided through a systematic review. We reviewed studies detailing quantitative research of persuasive message repetition and/or message fatigue published in communication journals between 1970 and 2020. Among other things, our review indicates that the field’s theorizing in this area often focuses on descriptive models but (1) infrequently considers explanatory principles and (2) rarely makes explicit arguments for the mechanisms driving the effects of persuasive message repetition or message fatigue. We consider what these findings tell us about the field’s theoretical contributions and suggest an agenda for future work.