Petar (Pero) Dragila was born in 1907 in Slavonia, Croatia. He finished Jesuit high school in Osijek. After graduation, he began working as a teacher in a Slavonian village. He was a sympathizer of radical left since his youth. In 1937 he became a member of the Communist Party of Yugoslavia (CPY). During the Second World War, Dragila did not participate in the partisan units, but he was active in the illegal Communist movement. In 1944 he became a member of the Anti-fascist Council for National Liberation of Yugoslavia (in Serbo-Croatian Anti-fašističko veće narodnog oslobođenja Jugoslavije - AVNOJ). In March 1945 he became a major of the state security agency, the Department for People's Protection (in Serbo-Croatian Odeljenje za zaštitu naroda or OZNA), in Slavonia. His task was to create a network of agents in surrounding areas (Italy, the Free Territory of Trieste, Austria and Hungary), infiltrate political refugees and search for war criminals. At the Zagreb headquarters of OZNA he also met his future wife Dušanka.

In 1946, the Dragila couple was sent to Washington, D.C., to work within the Yugoslav diplomatic mission. Pero Dragila officially worked as the secretary of the Yugoslav Embassy in Washington. Unofficially, he was involved in espionage as Deputy Chief of the State Security Service (in Serbo-Croatian Uprava državne bezbednosti or UDBA) in order to monitor organisations of Yugoslav emigrants in the USA and Canada.

The Cominform Resolution of 1948 came as a surprise for Dragila. However, he decided to support the Internationalists and their policy in line with the Cominform and the Soviet Union. Since his position in the Yugoslav state administration was political, he was forced to resign. In August 1948, he arrived in Prague together with other Yugoslav diplomats who had taken a pro-Soviet stance.

Pero Dragila was one of the organisers of the Yugoslav Cominformist emigrant group in Prague. Up until 1954, Dragila was one of the leading and most influential members of this group, as well as the editor of the newspaper Nova Borba and directed Yugoslav emigrant radio broadcasting in Prague. However, given his previous work in UDBA, his main role among the Yugoslav Cominformists became intelligence activities, ensuring that spies did not infiltrate the organisation.

When the activities of the Yugoslav Cominformist emigrants restarted in the 1970s, leading to the formation of the new illegal Communist Party of Yugoslavia (CPY), Dragila became a member of the party’s Central Committee. Together with his wife Dušanka and Ivan Sinanovič, Dragila operated the so-called Prague cell of the new CPY, which became the centre for the production and distribution of illegal propaganda intended for Yugoslavia. Pero and Dušanka Dragila were the main authors of such leaflets, which were illegally printed and sent to Yugoslavia up until 1976. These leaflets now make up the Yugoslav Cominformists in Prague collection.

Pero Dragila never renounced his radical leftist attitudes. Starting from the Cominform Resolution of 1948, he acted as principled and steadfast anti-Titoist. He was never apprehended by the Yugoslav regime. He spent the rest of his life in Prague.