The University of Santo Tomas organized the UST ROTC in 1936 making it one of the first institutions to implement the National Defense Act of the Commonwealth Government. The officer tasked to organize the first cadet corps was 1Lt. Ceferino Garcia. Prof Juan Nakpil was comissioned to design their gala uniform for parade purposes. Maj. Alfredo Ramirez assumed his post as the first commandant on September 28, 1936. Seven hundred enthusiastic male students made up the first batch of ROTC cadets.

Cadet Enrique Quema, who later became the Assistant Secretary for President Garcia, served as the first Corps Commander. Cadet Colonel Mariano Alimurung later on took over Quema's post and was awarded the Sword of High Command by the Cross and Sabers Fraternity. Alimurung became the first Filipino doctor to successfully perform a heart transplant and is one of the founders of the Makati Medical Center.

In more than just a month of organization and training, the Corps marched for the first time before the viewing public during the first Commonwealth anniversary parade on November 15, 1936. The Corps' uniform at that early stage, were of bluish color with the pants having an inch-wide gold stripe piping. They used a tin-helmet that resembles the ones worn by the French troops during the Second World War. It was later changed to khaki with waist length shirt and tan shoes.

The first regent was Rev. Fr. Jesus Valbuena, O.P. who was then the Secretary General of the University. He was succeeded in 1938 by the Very Rev. Fr. Jose Ortega, O.P. Cadet Alimurung, who called himself "Cadet Marila", was the first Cadet Editor, then called "Brigade Editor" to the Varsitarian. He was succeeded in 1939 by Jose Feria, who called himself "Cadet Jofre", both as Corps Commander and Brigade Editor.

A year after the Corps was established, the Rector Magnificus of the University created the Honorary Corps of Lady Sponsors (1937) with Miss Maria Aurora Quezon, the president's daughter, as the first Honorary Colonel - the Lady Sponsor of the High Command. After only a year of existence, the Corps obtained the rating of "Superior" - the highest rating by milirary standards - in the annual tactical inspection. During the first inter-ROTC meet, the Corps rated second fiddle of the more experienced State University (UP) ROTC Unit.

The Corps grew bigger and better from a regiment (4 battalions, around 800 cadets), it grew to a brigade numbering more than 1,500 cadets. During the XXXIII International Eucharistic Congress held in Manila on February 3-7, 1937, the Corps participated and garnerned countless awards and praises.

On March 1939, the first batch of Advance ROTC Cadets graduated in a precedent setting ceremony. They were 24, among them: