He then attended San Carlos Seminary in Mandaluyong as a second-year Philosophy student from 1925 to 1926 under the Spanish Vincentians, and later completed his Theology studies under the SVD Fathers in Vigan from 1926 to 1929.

Less than a year after taking on his pastoral duties, he was sent to Rome in 1932 to study Canon Law at the Pontifical Institute of St. Apollinare, and graduated on January 8, 1937.

[3][5] In a secret consistory on December 16, 1937, Pope Pius XI appointed Madriaga as an auxiliary to Bishop Francisco Reyes of Nueva Caceres.

On May 23 of the same year, he took possession of the diocese and was consecrated the next day by Archbishop Gabriel Reyes of Cebu together with several other bishops of the Philippine hierarchy.

[7] He repeatedly requested the Holy See for the transfer of the seat of the diocese from Lingayen to Dagupan after the former was destroyed during World War II.

[10] Madriaga was reputed to be the official heraldist of the Catholic Church in the Philippines,[2] having designed more than a hundred coats of arms of dioceses and prelates.

Majority of his work during the 1950s are published in the Boletin Eclesiastico de Filipinas, a monthly interdiocesan bulletin managed by the University of Santo Tomas.