 The politics of Croatia are defined by a parliamentary , representative democratic republic framework , where the Prime Minister of Croatia is the head of government in a multi @-@ party system . Executive power is exercised by the Government and the President of Croatia . Legislative power is vested in the Croatian Parliament ( Croatian : Sabor ) . The <unk> is independent of the executive and the legislature . The parliament adopted the current Constitution of Croatia on 22 December 1990 and decided to declare independence from Yugoslavia . The declaration of independence came into effect on 8 October 1991 . The constitution has since been amended several times . The first modern parties in the country developed in the middle of the 19th century , and their agenda and appeal changed , reflecting major social changes , such as the breakup of Austria @-@ Hungary , the Kingdom of Serbs , Croats and Slovenes , dictatorship and social upheavals in the kingdom , World War II , the establishment of Communist rule and the breakup of the <unk> Yugoslavia . 
