Vrablec was ordained as a Catholic priest on December 23, 1950, in Italy,[4] because of the Communist Government of Czechoslovakia and the persecution of the Roman Catholic Church by the government. He served as priest in Italy, and was the Rector of the Pontifical College of St. Cyril and Methodius for the Slovaks in Rome. On June 19, 1998, he was appointed as titular bishop of Thasbalta and Auxiliary Bishop of Bratislava-Trnava, until his retirement on April 2, 2004.[4]