Budisavljević studied law in Zagreb and Berlin before being elected to the Sabor of the Kingdom of Croatia-Slavonia in 1908 as a representative of the Croat-Serb Coalition led by Frano Supilo and Svetozar Pribičević.

In 1918, Budisavljević was among founders and the secretary of the National Council of Slovenes, Croats and Serbs – a body composed of political representatives of the South Slavs living in Austria-Hungary tasked with achieving independence of South Slavic lands from the empire.

In the same year he launched the Glas Slovenaca, Hrvata i Srba ("Voice of Slovenes, Croats and Serbs") journal.

In the same period he held several ministerial positions in Yugoslav governments including the government-in-exile during the World War II.

In 1958, he published Stvaranje države Srba, Hrvata i Slovenaca ("Creation of the state of Serbs, Croats and Slovenes").