Looking for work following his graduation, he approached Levy Hermanos, the owner of the well-known La Estrella del Norte studio in Manila.
Castrillo broke onto the Filipino arts scene in 1966, when he held his first one-man show at the Northern Motors showroom in Makati, Rizal.
That same year, his first major public sculptures were unveiled – “The Virgin” at La Loma Cemetery and “Youth's Cry of Defiance” in Fort Santiago, Manila.
He traveled extensively abroad on cultural visits, giving lectures and conducting research into the origins of early Filipino art.
Castrillo's main medium was metal, especially brass, bronze and steel, from which he created sculptures by hammering, cutting and welding, with the help of a group of assistants.
(documentation of the "Huling Hapunan", the depiction of the Last Supper with Christ and the Twelve Apostles, a large-scale sculpture project of Eduardo Castrillo)