The same period saw him dragged into the Austrian and Hungarian Revolutions. Like many Romanians, Mocioni supported the former's liberal reforms, and remained loyal to Franz Joseph I, opposing the rise of Hungarian nationalism. This pitted him against the pro-Hungarian revolutionary Eftimie Murgu, who enlisted the loyalties of various other Banatians. The Hungarian State reacted by confiscating Mocioni's property and forcing him into exile. By September 1849, he was in Vienna, where he acted as a Romanian representative, alongside Ioan Dobran and Vincențiu Babeș. Petru Mocioni was also active there as a "man of trust" of the Banatian Romanians, presenting Franz Stadion with a set of political proposals on their behalf.