We have analyzed the behaviour of primary fiscal balance and public debt in Serbia before and in the aftermath of the global financial crisis. The results of our analysis are: i) public debt to GDP ratioexhibits (near) unit root behaviour with an overall upward time trend; ii) the response of primary fiscal balance to public debt has been insufficient to mean revert the upward trend in government debt; iii) the efforts of the Serbian government to repay the debt principal after the fiscal rule breach have not been persistent, providing empirical support to the fiscal fatigue hypothesis; iv) the government budget constraint has deteriorated since the beginning of the global financial crisis; v) the response of primary fiscal balance to public debt from the onset of the global financial crisis has dropped more severely in comparison to other European economies.