Burundi's economic output is expected to shrink by 7.2 percent this year after 4.7 percent growth in 2014, but expand again by 5.2 percent in 2016, the International Monetary Fund said.
The forecasts, contained in the latest World Economic Outlook for October seen by Reuters on Thursday, did not give the reason behind the latest projections.
But the country has been in political turmoil since April, when President Pierre Nkurunziza said he would run for a third term in office.
Opponents said another five-year term, which he began in August, violated a peace deal that ended a 12-year civil war in 2005, a conflict that left Burundi awash with arms.
In a sign of slowing economic activity, Burundi's tax revenues have been falling ever since. The latest data from the revenue authority show tax collections dropped 31.8 percent below target in August when it collected 42.2 billion Burundian francs ($27.51 million), against a target of 61.9 billion francs.
The tax revenue was also 20.4 percent lower than the amount collected in August 2014.
Although months of protests and an attempted coup in May were quelled, sporadic violence and killings continue to take place in the capital and some rural districts.
In the last forecast for Burundi in April, the IMF had projected a 4.8 percent economic growth for Burundi.
The U.N. refugee agency says more than 181,000 people have fled Burundi due to the violence.