Luciano P.R. Santiago (1943-2019) was a prolific Filipino writer and historian who is best remembered for his studies on genealogy, art history, and religious history. These works earned him many accolades, including two National Book Awards in 1990 and 2005. As a medical doctor by profession, Santiago also endeavored to understand the origins and development of medicine and its various specializations in the Philippines in the late 19th century. For example, he paid close attention to psychiatry, his own medical specialization, and its emergence in the islands, which he had closely linked with Jose Rizal, leading to several publications in both historical and medical journals. This historiographic essay aims to revisit and assess Santiago’s works on the history of medicine in the Philippines. It argues that although this body of works deals primarily with medical topics, they nevertheless reflect Santiago’s personal and broader interests in genealogy and historical firsts. And while the author did not produce what other scholars would characterize as groundbreaking interpretations, outlines, and frameworks, his writings still hold significant value in historiography. This is due to Santiago’s excellent usage of important primary sources, such as archival materials, correspondences, and interviews, and his successful attempts in retrieving lesser-known information and personalities in Philippine history.