Slavoljub Muslin has been sacked as Serbia's coach despite the nation's recent qualification for next summer's World Cup.
Muslin, 64, guided Serbia to top spot in European qualifying Group D, thus securing the Eagles a place at Russia 2018, but the country's football association has opted to make a change.
In a statement published on its website on Monday, the FSS said: "The termination of Slavoljub Muslin's contract has been agreed and Mladen Krstajic is now in charge of team selection.
"The FSS thanks the former head coach for his cooperation and results. Krstajic will lead the team in the next two friendly matches against China and South Korea."
After eight years of failing to make it to a major championship, Serbia qualified for next year's World Cup for the second time since becoming an independent nation in 2006.
Serbian football officials have criticised Muslin for his team selection, defensive tactics and for failing to bring in young players, especially talented Lazio midfielder Sergej Milinkovic-Savic.
"We parted ways because we don't think alike on how the team should look for the World Cup in Russia,'' Muslin was quoted as saying by Serbian media.
The 64-year-old Muslin took over the national team in 2016 after coaching mostly French, Belgian and Russian clubs.
Former Werder Bremen and Schalke defender Krstajic earned 59 caps for Serbia across nine years.
Information from Press Association and The Associated Press was used in this report.