In 1943 alongside Karol Šmidke he was deployed in Poland and entered Slovakia in order to conduct the Slovak National Uprising.

[1] After the liberation of Czechoslovakia, he worked in important political positions in the Communist Party of Slovakia.

He applied repressive measures, as the Minister of National Security, he prepared the political processes of the early 1950s in Czechoslovakia, including the Slánský Trial.

Together Viliam Široký he was an initiator of the purging of the so called "bourgeois nationalists" within the KPS leadership.

After the Kolder Commission revised some of the political processes of the 1950s, Bacílek was removed from all public and party positions.