Thomasian blood and sweat flooded the battlefields of World War II. Two Thousand (2,000) cadets volunteered for the defense of the country. After the war, on September 13, 1946, the ROTC program was reactivated through General Orders No. 528, HPA under new rules and with a strength of 2,000 men. The commandant was former Major Manuel Cabal who later became the AFP's top brass. The first post war Corps Commander was Roberto Maravillas. He succeeded Ramon Diaz, The Corps Commander before the war broke out in 1941.

On January 1948, the Cross and Sabers Fraternity presented to the Honorary Corps of Lady Sponsors their fraternity pins in what seemed to be the first post war activity of its kind, perhaps even the first of its kind. The Corps Commander was C/Col Constante Agbayani.