This brief communication commemorates the 100th anniversary of the birth of Reynaldo Alarcón Napurí and briefly reviews his contributions to the history of psychology in Peru and Latin America. Alarcón academic career spanned over seven decades and encompassed multiple research interests, one of which was the history of psychology. It is concluded that his historiographical work, as a whole, marked a significant milestone that has served as a reference point for delving into various aspects of the history of Peruvian psychology as both a science and a profession. (PsycInfo Database Record (c) 2025 APA, all rights reserved).