The University of San Carlos and the Protomedicato of Guatemala series includes various scholarly materials, including degree awards, final exams, financial information for the University, rector’s records, degree awards, and materials from the Saint Thomas Aquinas school that predated the University of San Carlos. This series, which is the bulk of the collection, contains some of the oldest and most fragile documents in the collection.

Records are mostly organized chronologically. At times the handwriting and spelling are difficult to read, so Spencer staff have used [brackets] in folder titles to indicate uncertainty when needed. "Quotations" have been used in this series for items that had formal titles on cover pages or are quoting from information provided by Griffith at time of donation.