Public debt is the amount that the government borrows from creditors to finance realized deficits. This paper deals with public debt in theoretical and practical terms. Public debt has a fiscal and monetary function, and therefore represents an important factor in the national economy, and as such affects the country's economic growth. The impact of public debt can be differentiated in the short and long term. ln the short run, public debt can improve and accelerate economic growth if he government borrows justifiably. A short-term acceleration in economic growth may occur when a country invests in public services. There is also a long-term impact of public debt, which has an impact on the instability and burden on the economy. The increase in public debt is most often associated with modem finance, public debt policy affects the movement of economic policy of the country, and especially fiscal and monetary policy. Public debt policies ensure the sustainability of public debt, while irresponsible and improper public debt management leads to unsustainable public debt. In the practical part of the paper, the public debt is analyzed on the example of the Republic of Croatia, according to the type of instrument, maturity and currency and interest rate structure. The general movement of public debt over the years is also shown. Some progress has been made on public debt management policy, but there is still room for improvement.